String.Compare Method

Reference

Definition

Namespace:: System

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Compares two specified String objects and returns an integer that indicates their relative position in the sort order.

Overloads

Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions)	Compares substrings of two specified String objects using the specified comparison options and culture-specific information to influence the comparison, and returns an integer that indicates the relationship of the two substrings to each other in the sort order.
Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)	Compares substrings of two specified String objects, ignoring or honoring their case and using culture-specific information to influence the comparison, and returns an integer that indicates their relative position in the sort order.
Compare(String, Int32, String, Int32, Int32, StringComparison)	Compares substrings of two specified String objects using the specified rules, and returns an integer that indicates their relative position in the sort order.
Compare(String, Int32, String, Int32, Int32, Boolean)	Compares substrings of two specified String objects, ignoring or honoring their case, and returns an integer that indicates their relative position in the sort order.
Compare(String, Int32, String, Int32, Int32)	Compares substrings of two specified String objects and returns an integer that indicates their relative position in the sort order.
Compare(String, String, CultureInfo, CompareOptions)	Compares two specified String objects using the specified comparison options and culture-specific information to influence the comparison, and returns an integer that indicates the relationship of the two strings to each other in the sort order.
Compare(String, String, Boolean, CultureInfo)	Compares two specified String objects, ignoring or honoring their case, and using culture-specific information to influence the comparison, and returns an integer that indicates their relative position in the sort order.
Compare(String, String, StringComparison)	Compares two specified String objects using the specified rules, and returns an integer that indicates their relative position in the sort order.
Compare(String, String, Boolean)	Compares two specified String objects, ignoring or honoring their case, and returns an integer that indicates their relative position in the sort order.
Compare(String, String)	Compares two specified String objects and returns an integer that indicates their relative position in the sort order.

Remarks

All overloads of the Compare method return a 32-bit signed integer indicating the lexical relationship between the two comparands.

Value	Condition
Less than zero	The first substring precedes the second substring in the sort order.
Zero	The substrings occur in the same position in the sort order, or `length` is zero.
Greater than zero	The first substring follows the second substring in the sort order.

Warning

Whenever possible, you should call an overload of the Compare method that includes a StringComparison parameter. For more information, see Best Practices for Using Strings.

Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares substrings of two specified String objects using the specified comparison options and culture-specific information to influence the comparison, and returns an integer that indicates the relationship of the two substrings to each other in the sort order.

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length, System::Globalization::CultureInfo ^ culture, System::Globalization::CompareOptions options);

public static int Compare (string? strA, int indexA, string? strB, int indexB, int length, System.Globalization.CultureInfo? culture, System.Globalization.CompareOptions options);

public static int Compare (string strA, int indexA, string strB, int indexB, int length, System.Globalization.CultureInfo culture, System.Globalization.CompareOptions options);

static member Compare : string * int * string * int * int * System.Globalization.CultureInfo * System.Globalization.CompareOptions -> int

Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer, culture As CultureInfo, options As CompareOptions) As Integer

Parameters

strA: String

The first string to use in the comparison.

indexA: Int32

The starting position of the substring within strA.

strB: String

The second string to use in the comparison.

indexB: Int32

The starting position of the substring within strB.

length: Int32

The maximum number of characters in the substrings to compare.

culture: CultureInfo

An object that supplies culture-specific comparison information. If culture is null, the current culture is used.

options: CompareOptions

Options to use when performing the comparison (such as ignoring case or symbols).

Returns

Int32

An integer that indicates the lexical relationship between the two substrings, as shown in the following table.

Value	Condition
Less than zero	The substring in `strA` precedes the substring in `strB` in the sort order.
Zero	The substrings occur in the same position in the sort order, or `length` is zero.
Greater than zero	The substring in `strA` follows the substring in `strB` in the sort order.

Exceptions

ArgumentException

options is not a CompareOptions value.

ArgumentOutOfRangeException

indexA is greater than strA.Length.

-or-

indexB is greater than strB.Length.

-or-

indexA, indexB, or length is negative.

-or-

Either strA or strB is null, and length is greater than zero.

Examples

The following example uses the Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) method to compare the last names of two people. It then lists them in alphabetical order.

string name1 = "Jack Smith";
string name2 = "John Doe";

// Get position of character after the space character.
int index1 = name1.IndexOf(" ");
index1 = index1 < 0 ? 0 : ++index1;

int index2 = name2.IndexOf(" ");
index2 = index2 < 0 ? 0 : ++index2;

int length = Math.Max(name1.Length, name2.Length);

Console.WriteLine("Sorted alphabetically by last name:");
if (String.Compare(name1, index1, name2, index2, length,
                   new CultureInfo("en-US"), CompareOptions.IgnoreCase) < 0)
    Console.WriteLine("{0}\n{1}", name1, name2);
else
    Console.WriteLine("{0}\n{1}", name2, name1);

// The example displays the following output:
//       Sorted alphabetically by last name:
//       John Doe
//       Jack Smith

open System
open System.Globalization

let name1 = "Jack Smith"
let name2 = "John Doe"

// Get position of character after the space character.
let index1 =
    let i = name1.IndexOf " "
    if i < 0 then 0 else i + 1

let index2 = 
    let i = name2.IndexOf " "
    if i < 0 then 0 else i + 1

let length = max name1.Length name2.Length

printfn "Sorted alphabetically by last name:"
if String.Compare(name1, index1, name2, index2, length, CultureInfo "en-US", CompareOptions.IgnoreCase) < 0 then
    printfn $"{name1}\n{name2}"
else
    printfn $"{name2}\n{name1}"

// The example displays the following output:
//       Sorted alphabetically by last name:
//       John Doe
//       Jack Smith

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim name1 As String = "Jack Smith"
      Dim name2 = "John Doe"
      
      ' Get position of space character.
      Dim index1 As Integer = name1.IndexOf(" ")
      index1 = CInt(IIf(index1 < 0, 0, index1 - 1))
      
      Dim index2 As Integer = name2.IndexOf(" ")
      index1 = CInt(IIf(index1 < 0, 0, index1 - 1))
      
      Dim length As Integer = Math.Max(name1.Length, name2.Length)
      
      Console.WriteLIne("Sorted alphabetically by last name:")
      If String.Compare(name1, index1, name2, index2, length, _
                        New CultureInfo("en-US"), CompareOptions.IgnoreCase) < 0 Then
         Console.WriteLine("{0}{1}{2}", name1, vbCrLf, name2)
      Else
         Console.WriteLine("{0}{1}{2}", name2, vbCrLf, name1)
      End If
   End Sub
End Module
' The example displays the following output;
'       Sorted alphabetically by last name:
'       John Doe
'       Jack Smith

Remarks

The substrings to compare start in strA at position indexA and in strB at position indexB. The length of the first substring is the length of strA minus indexA. The length of the second substring is the length of strB minus indexB.

The number of characters to compare is the lesser of the lengths of the two substrings, and length. The indexA, indexB, and length parameters must be nonnegative.

The comparison uses the culture parameter to obtain culture-specific information, such as casing rules and the alphabetical order of individual characters. For example, a particular culture could specify that certain combinations of characters be treated as a single character, that uppercase and lowercase characters be compared in a particular way, or that the sort order of a character depends on the characters that precede or follow it.

Caution

The Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) method is designed primarily for use in sorting or alphabetizing operations. It should not be used when the primary purpose of the method call is to determine whether two substrings are equivalent (that is, when the purpose of the method call is to test for a return value of zero). To determine whether two strings are equivalent, call the Equals method.

One or both of strA and strB can be null. By definition, any string, including String.Empty, compares greater than a null reference, and two null references compare equal to each other.

The comparison can be further specified by the options parameter, which consists of one or more members of the System.Globalization.CompareOptions enumeration. However, because the purpose of this method is to conduct a culture-sensitive string comparison, the CompareOptions.Ordinal and CompareOptions.OrdinalIgnoreCase values have no effect.

The comparison terminates when an inequality is discovered or both substrings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, the string with the remaining characters is considered greater. The return value is the result of the last comparison performed.

Notes to Callers

Character sets include ignorable characters. The Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) method does not consider these characters when it performs a linguistic or culture-sensitive comparison. To recognize ignorable characters in your comparison, supply a value of Ordinal or OrdinalIgnoreCase for the options parameter.

Applies to

Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares substrings of two specified String objects, ignoring or honoring their case and using culture-specific information to influence the comparison, and returns an integer that indicates their relative position in the sort order.

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length, bool ignoreCase, System::Globalization::CultureInfo ^ culture);

public static int Compare (string? strA, int indexA, string? strB, int indexB, int length, bool ignoreCase, System.Globalization.CultureInfo? culture);

public static int Compare (string strA, int indexA, string strB, int indexB, int length, bool ignoreCase, System.Globalization.CultureInfo culture);

static member Compare : string * int * string * int * int * bool * System.Globalization.CultureInfo -> int

Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer, ignoreCase As Boolean, culture As CultureInfo) As Integer

Parameters

strA: String

The first string to use in the comparison.

indexA: Int32

The position of the substring within strA.

strB: String

The second string to use in the comparison.

indexB: Int32

The position of the substring within strB.

length: Int32

The maximum number of characters in the substrings to compare.

ignoreCase: Boolean

true to ignore case during the comparison; otherwise, false.

culture: CultureInfo

An object that supplies culture-specific comparison information. If culture is null, the current culture is used.

Returns

Int32

An integer that indicates the lexical relationship between the two comparands.

Value	Condition
Less than zero	The substring in `strA` precedes the substring in `strB` in the sort order.
Zero	The substrings occur in the same position in the sort order, or `length` is zero.
Greater than zero	The substring in `strA` follows the substring in `strB` in the sort order.

Exceptions

ArgumentOutOfRangeException

indexA is greater than strA.Length.

-or-

indexB is greater than strB.Length.

-or-

indexA, indexB, or length is negative.

-or-

Either strA or strB is null, and length is greater than zero.

Examples

The following example compares two substrings using different cultures and ignoring the case of the substrings. The choice of culture affects how the letter "I" is compared.

// Sample for String::Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)
using namespace System;
using namespace System::Globalization;
int main()
{
   
   //                0123456
   String^ str1 = "MACHINE";
   String^ str2 = "machine";
   String^ str;
   int result;
   Console::WriteLine();
   Console::WriteLine( "str1 = '{0}', str2 = '{1}'", str1, str2 );
   Console::WriteLine( "Ignore case, Turkish culture:" );
   result = String::Compare( str1, 4, str2, 4, 2, true, gcnew CultureInfo( "tr-TR" ) );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in '{1}' is ", str1->Substring( 4, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in '{1}'.", str2->Substring( 4, 2 ), str2 );
   Console::WriteLine();
   Console::WriteLine( "Ignore case, invariant culture:" );
   result = String::Compare( str1, 4, str2, 4, 2, true, CultureInfo::InvariantCulture );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in '{1}' is ", str1->Substring( 4, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in '{1}'.", str2->Substring( 4, 2 ), str2 );
}

/*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case, Turkish culture:
Substring 'IN' in 'MACHINE' is less than substring 'in' in 'machine'.

Ignore case, invariant culture:
Substring 'IN' in 'MACHINE' is equal to substring 'in' in 'machine'.
*/

// Sample for String.Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)
using System;
using System.Globalization;

class Sample5
{
    public static void Main()
    {
        //                 0123456
        String str1 = "MACHINE";
        String str2 = "machine";
        String str;
        int result;

        Console.WriteLine();
        Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);
        Console.WriteLine("Ignore case, Turkish culture:");
        result = String.Compare(str1, 4, str2, 4, 2, true, new CultureInfo("tr-TR"));
        str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
        Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(4, 2), str1);
        Console.Write("{0} ", str);
        Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(4, 2), str2);

        Console.WriteLine();
        Console.WriteLine("Ignore case, invariant culture:");
        result = String.Compare(str1, 4, str2, 4, 2, true, CultureInfo.InvariantCulture);
        str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
        Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(4, 2), str1);
        Console.Write("{0} ", str);
        Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(4, 2), str2);
    }
}
/*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case, Turkish culture:
Substring 'IN' in 'MACHINE' is less than substring 'in' in 'machine'.

Ignore case, invariant culture:
Substring 'IN' in 'MACHINE' is equal to substring 'in' in 'machine'.
*/

// Sample for String.Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)
open System
open System.Globalization

//                 0123456
let str1 = "MACHINE"
let str2 = "machine"

printfn $"\nstr1 = '{str1}', str2 = '{str2}'"
printfn "Ignore case, Turkish culture:"
let result = String.Compare(str1, 4, str2, 4, 2, true, CultureInfo "tr-TR")
let str = if result < 0 then "less than" elif result > 0 then "greater than" else "equal to"
printf $"Substring '{str1.Substring(4, 2)}' in '{str1}' is "
printf $"{str} "
printfn $"substring '{str2.Substring(4, 2)}' in '{str2}'."

printfn "\nIgnore case, invariant culture:"
let result2 = String.Compare(str1, 4, str2, 4, 2, true, CultureInfo.InvariantCulture)
let str3 = if result < 0 then "less than" elif result > 0 then "greater than" else "equal to"
printf $"Substring '{str1.Substring(4, 2)}' in '{str1}' is "
printf $"{str3} "
printfn $"substring '{str2.Substring(4, 2)}' in '{str2}'."

(*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case, Turkish culture:
Substring 'IN' in 'MACHINE' is less than substring 'in' in 'machine'.

Ignore case, invariant culture:
Substring 'IN' in 'MACHINE' is equal to substring 'in' in 'machine'.
*)

' Sample for String.Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)
Imports System.Globalization

Class Sample
   
   Public Shared Sub Main()
      '                       0123456
      Dim str1 As [String] = "MACHINE"
      Dim str2 As [String] = "machine"
      Dim str As [String]
      Dim result As Integer
      
      Console.WriteLine()
      Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2)
      Console.WriteLine("Ignore case, Turkish culture:")
      result = [String].Compare(str1, 4, str2, 4, 2, True, New CultureInfo("tr-TR"))
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(4, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(4, 2), str2)
      
      Console.WriteLine()
      Console.WriteLine("Ignore case, invariant culture:")
      result = [String].Compare(str1, 4, str2, 4, 2, True, CultureInfo.InvariantCulture)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(4, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(4, 2), str2)
   End Sub
End Class
'
'This example produces the following results:
'
'str1 = 'MACHINE', str2 = 'machine'
'Ignore case, Turkish culture:
'Substring 'IN' in 'MACHINE' is less than substring 'in' in 'machine'.
'
'Ignore case, invariant culture:
'Substring 'IN' in 'MACHINE' is equal to substring 'in' in 'machine'.
'

Remarks

The substrings to compare start in strA at indexA, and in strB at indexB. Both indexA and indexB are zero-based; that is, the first character in strA and strB is at position zero, not position one. The length of the first substring is equal to the length of strA minus indexA plus one. The length of the second substring is equal to the length of strB minus indexB plus one.

The number of characters to compare is the lesser of the lengths of the two substrings, and length. The indexA, indexB, and length parameters must be nonnegative.

The comparison uses the culture parameter to obtain culture-specific information such as casing rules and the alphabetic order of individual characters. For example, a culture could specify that certain combinations of characters be treated as a single character, or uppercase and lowercase characters be compared in a particular way, or that the sorting order of a character depends on the characters that precede or follow it.

The comparison is performed using word sort rules. For more information about word, string, and ordinal sorts, see System.Globalization.CompareOptions.

One or both comparands can be null. By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.

The comparison terminates when an inequality is discovered or both substrings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, then the string with remaining characters is considered greater. The return value is the result of the last comparison performed.

Unexpected results can occur when comparisons are affected by culture-specific casing rules. For example, in Turkish, the following example yields the wrong results because the file system in Turkish does not use linguistic casing rules for the letter "i" in "file".

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, true) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Notes to Callers

Character sets include ignorable characters. The Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo) method does not consider these characters when it performs a linguistic or culture-sensitive comparison. To recognize ignorable characters in your comparison, call the Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) method and supply a value of Ordinal or OrdinalIgnoreCase for the options parameter.

Applies to

Compare(String, Int32, String, Int32, Int32, StringComparison)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares substrings of two specified String objects using the specified rules, and returns an integer that indicates their relative position in the sort order.

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length, StringComparison comparisonType);

public static int Compare (string strA, int indexA, string strB, int indexB, int length, StringComparison comparisonType);

public static int Compare (string? strA, int indexA, string? strB, int indexB, int length, StringComparison comparisonType);

static member Compare : string * int * string * int * int * StringComparison -> int

Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer, comparisonType As StringComparison) As Integer

Parameters

strA: String

The first string to use in the comparison.

indexA: Int32

The position of the substring within strA.

strB: String

The second string to use in the comparison.

indexB: Int32

The position of the substring within strB.

length: Int32

The maximum number of characters in the substrings to compare.

comparisonType: StringComparison

One of the enumeration values that specifies the rules to use in the comparison.

Returns

Int32

A 32-bit signed integer that indicates the lexical relationship between the two comparands.

Value	Condition
Less than zero	The substring in `strA` precedes the substring in `strB` in the sort order.
Zero	The substrings occur in the same position in the sort order, or the `length` parameter is zero.
Greater than zero	The substring in `strA` follows the substring in `strB` in the sort order.

Exceptions

ArgumentOutOfRangeException

indexA is greater than strA.Length.

-or-

indexB is greater than strB.Length.

-or-

indexA, indexB, or length is negative.

-or-

Either indexA or indexB is null, and length is greater than zero.

ArgumentException

comparisonType is not a StringComparison value.

Examples

The following example compares two substrings.

// Sample for String::Compare(String, Int32, String, Int32, Int32)
using namespace System;
int main()
{
   
   //                0123456
   String^ str1 = "machine";
   String^ str2 = "device";
   String^ str;
   int result;
   Console::WriteLine();
   Console::WriteLine( "str1 = '{0}', str2 = '{1}'", str1, str2 );
   result = String::Compare( str1, 2, str2, 0, 2 );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in ' {1}' is ", str1->Substring( 2, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in ' {1}'.", str2->Substring( 0, 2 ), str2 );
}

/*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*/

String str1 = "machine";
String str2 = "device";
String str;
int result;

Console.WriteLine();
Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);
result = String.Compare(str1, 2, str2, 0, 2);
str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
Console.Write("{0} ", str);
Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(0, 2), str2);

/*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*/

open System

let str1 = "machine"
let str2 = "device"

printfn "\nstr1 = '{str1}', str2 = '{str2}'"

let result = String.Compare(str1, 2, str2, 0, 2)
let str = 
    if result < 0 then "less than" 
    elif result > 0 then "greater than" 
    else "equal to"

printf $"Substring '{str1.Substring(2, 2)}' in '{str1}' is "
printf $"{str} "
printfn $"substring '{str2.Substring(0, 2)}' in '{str2}'."

(*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*)

' Sample for String.Compare(String, Int32, String, Int32, Int32)
Class Sample
   Public Shared Sub Main()
      '                       0123456
      Dim str1 As [String] = "machine"
      Dim str2 As [String] = "device"
      Dim str As [String]
      Dim result As Integer
      
      Console.WriteLine()
      Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2)
      result = [String].Compare(str1, 2, str2, 0, 2)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(0, 2), str2)
   End Sub
End Class
'
'This example produces the following results:
'
'str1 = 'machine', str2 = 'device'
'Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
'

Remarks

The substrings to compare start in strA at indexA and in strB at indexB. Both indexA and indexB are zero-based; that is, the first character in strA and strB is at position zero, not position one. The length of the first substring is equal to the length of strA minus indexA plus one. The length of the second substring is equal to the length of strB minus indexB plus one.

The number of characters to compare is the lesser of the lengths of the two substrings, and length. The indexA, indexB, and length parameters must be nonnegative.

The comparisonType parameter indicates whether the comparison should use the current or invariant culture, honor or ignore the case of the comparands, or use word (culture-sensitive) or ordinal (culture-insensitive) sort rules.

One or both comparands can be null. By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.

The comparison terminates when an inequality is discovered or both substrings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, the string with remaining characters is considered greater. The return value is the result of the last comparison performed.

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, true) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Notes to Callers

Character sets include ignorable characters. The Compare(String, Int32, String, Int32, Int32, StringComparison) method does not consider these characters when it performs a linguistic or culture-sensitive comparison. To recognize ignorable characters in your comparison, supply a value of Ordinal or OrdinalIgnoreCase for the comparisonType parameter.

Applies to

Compare(String, Int32, String, Int32, Int32, Boolean)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares substrings of two specified String objects, ignoring or honoring their case, and returns an integer that indicates their relative position in the sort order.

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length, bool ignoreCase);

public static int Compare (string? strA, int indexA, string? strB, int indexB, int length, bool ignoreCase);

public static int Compare (string strA, int indexA, string strB, int indexB, int length, bool ignoreCase);

static member Compare : string * int * string * int * int * bool -> int

Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer, ignoreCase As Boolean) As Integer

Parameters

strA: String

The first string to use in the comparison.

indexA: Int32

The position of the substring within strA.

strB: String

The second string to use in the comparison.

indexB: Int32

The position of the substring within strB.

length: Int32

The maximum number of characters in the substrings to compare.

ignoreCase: Boolean

true to ignore case during the comparison; otherwise, false.

Returns

Int32

A 32-bit signed integer that indicates the lexical relationship between the two comparands.

Value	Condition
Less than zero	The substring in `strA` precedes the substring in `strB` in the sort order.
Zero	The substrings occur in the same position in the sort order, or `length` is zero.
Greater than zero	The substring in `strA` follows the substring in `strB` in the sort order.

Exceptions

ArgumentOutOfRangeException

indexA is greater than strA.Length.

-or-

indexB is greater than strB.Length.

-or-

indexA, indexB, or length is negative.

-or-

Either indexA or indexB is null, and length is greater than zero.

Examples

The following example performs two comparisons of two substrings that only differ in case. The first comparison ignores case and the second comparison considers case.

// Sample for String::Compare(String, Int32, String, Int32, Int32, Boolean)
using namespace System;
int main()
{
   
   //                0123456
   String^ str1 = "MACHINE";
   String^ str2 = "machine";
   String^ str;
   int result;
   Console::WriteLine();
   Console::WriteLine( "str1 = '{0}', str2 = '{1}'", str1, str2 );
   Console::WriteLine( "Ignore case:" );
   result = String::Compare( str1, 2, str2, 2, 2, true );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in '{1}' is ", str1->Substring( 2, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in '{1}'.", str2->Substring( 2, 2 ), str2 );
   Console::WriteLine();
   Console::WriteLine( "Honor case:" );
   result = String::Compare( str1, 2, str2, 2, 2, false );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in '{1}' is ", str1->Substring( 2, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in '{1}'.", str2->Substring( 2, 2 ), str2 );
}

/*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case:
Substring 'CH' in 'MACHINE' is equal to substring 'ch' in 'machine'.

Honor case:
Substring 'CH' in 'MACHINE' is greater than substring 'ch' in 'machine'.
*/

String str1 = "MACHINE";
String str2 = "machine";
String str;
int result;

Console.WriteLine();
Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);

Console.WriteLine("Ignore case:");
result = String.Compare(str1, 2, str2, 2, 2, true);
str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
Console.Write("{0} ", str);
Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2);
Console.WriteLine();

Console.WriteLine("Honor case:");
result = String.Compare(str1, 2, str2, 2, 2, false);
str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
Console.Write("{0} ", str);
Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2);

/*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case:
Substring 'CH' in 'MACHINE' is equal to substring 'ch' in 'machine'.

Honor case:
Substring 'CH' in 'MACHINE' is greater than substring 'ch' in 'machine'.
*/

open System

let str1 = "MACHINE"
let str2 = "machine"

printfn $"\nstr1 = '{str1}', str2 = '{str2}'"

printfn "Ignore case:"
let result = String.Compare(str1, 2, str2, 2, 2, true)
let str = 
    if result < 0 then "less than" 
    elif result > 0 then "greater than"
    else "equal to"

printf $"Substring '{str1.Substring(2, 2)}' in '{str1}' is "
printf $"{str} "
printfn $"substring '{str2.Substring(2, 2)}' in '{str2}'.\n"

printfn "Honor case:"
let result2 = String.Compare(str1, 2, str2, 2, 2, false)
let str3 = 
    if result < 0 then "less than" 
    elif result > 0 then "greater than" 
    else "equal to"

printfn $"Substring '{str1.Substring(2, 2)}' in '{str1}' is "
printf $"{str3} "
printfn $"substring '{str2.Substring(2, 2)}' in '{str2}'."

(*
This example produces the following results:

str1 = 'MACHINE', str2 = 'machine'
Ignore case:
Substring 'CH' in 'MACHINE' is equal to substring 'ch' in 'machine'.

Honor case:
Substring 'CH' in 'MACHINE' is greater than substring 'ch' in 'machine'.
*)

' Sample for String.Compare(String, Int32, String, Int32, Int32, Boolean)
Class Sample
   
   Public Shared Sub Main()
      '                       0123456
      Dim str1 As [String] = "MACHINE"
      Dim str2 As [String] = "machine"
      Dim str As [String]
      Dim result As Integer
      
      Console.WriteLine()
      Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2)
      Console.WriteLine("Ignore case:")
      result = [String].Compare(str1, 2, str2, 2, 2, True)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2)
      
      Console.WriteLine()
      Console.WriteLine("Honor case:")
      result = [String].Compare(str1, 2, str2, 2, 2, False)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(2, 2), str2)
   End Sub
End Class
'
'This example produces the following results:
'
'str1 = 'MACHINE', str2 = 'machine'
'Ignore case:
'Substring 'CH' in 'MACHINE' is equal to substring 'ch' in 'machine'.
'
'Honor case:
'Substring 'CH' in 'MACHINE' is greater than substring 'ch' in 'machine'.
'

Remarks

The substrings to compare start in strA at indexA, and in strB at indexB. Both indexA and indexB are zero-based; that is, the first character in strA and strB is at position zero. The length of the first substring is equal to the length of strA minus indexA plus one. The length of the second substring is equal to the length of strB minus indexB plus one.

The number of characters to compare is the lesser of the lengths of the two substrings, and length. The indexA, indexB, and length parameters must be nonnegative.

The comparison uses the current culture to obtain culture-specific information such as casing rules and the alphabetic order of individual characters. For example, a culture could specify that certain combinations of characters be treated as a single character, or uppercase and lowercase characters be compared in a particular way, or that the sorting order of a character depends on the characters that precede or follow it.

The comparison is performed using word sort rules. For more information about word, string, and ordinal sorts, see System.Globalization.CompareOptions.

Warning

When comparing strings, you should call the Compare(String, Int32, String, Int32, Int32, StringComparison) method, which requires that you explicitly specify the type of string comparison that the method uses. For more information, see Best Practices for Using Strings.

One or both comparands can be null. By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.

The comparison terminates when an inequality is discovered or both substrings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, then the string with remaining characters is considered greater. The return value is the result of the last comparison performed.

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, true) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

The path name needs to be compared in an invariant manner. The correct code to do this is as follows.

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Notes to Callers

Character sets include ignorable characters. The Compare(String, Int32, String, Int32, Int32, Boolean) method does not consider these characters when it performs a linguistic or culture-sensitive comparison. To recognize ignorable characters in your comparison, call the Compare(String, Int32, String, Int32, Int32, StringComparison) method and supply a value of Ordinal or OrdinalIgnoreCase for the comparisonType parameter.

Applies to

Compare(String, Int32, String, Int32, Int32)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares substrings of two specified String objects and returns an integer that indicates their relative position in the sort order.

public:
 static int Compare(System::String ^ strA, int indexA, System::String ^ strB, int indexB, int length);

public static int Compare (string strA, int indexA, string strB, int indexB, int length);

public static int Compare (string? strA, int indexA, string? strB, int indexB, int length);

static member Compare : string * int * string * int * int -> int

Public Shared Function Compare (strA As String, indexA As Integer, strB As String, indexB As Integer, length As Integer) As Integer

Parameters

strA: String

The first string to use in the comparison.

indexA: Int32

The position of the substring within strA.

strB: String

The second string to use in the comparison.

indexB: Int32

The position of the substring within strB.

length: Int32

The maximum number of characters in the substrings to compare.

Returns

Int32

A 32-bit signed integer indicating the lexical relationship between the two comparands.

Value	Condition
Less than zero	The substring in `strA` precedes the substring in `strB` in the sort order.
Zero	The substrings occur in the same position in the sort order, or `length` is zero.
Greater than zero	The substring in `strA` follows the substring in `strB` in the sort order.

Exceptions

ArgumentOutOfRangeException

indexA is greater than strA.Length.

-or-

indexB is greater than strB.Length.

-or-

indexA, indexB, or length is negative.

-or-

Either indexA or indexB is null, and length is greater than zero.

Examples

The following example compares two substrings.

// Sample for String::Compare(String, Int32, String, Int32, Int32)
using namespace System;
int main()
{
   
   //                0123456
   String^ str1 = "machine";
   String^ str2 = "device";
   String^ str;
   int result;
   Console::WriteLine();
   Console::WriteLine( "str1 = '{0}', str2 = '{1}'", str1, str2 );
   result = String::Compare( str1, 2, str2, 0, 2 );
   str = ((result < 0) ? "less than" : ((result > 0) ? (String^)"greater than" : "equal to"));
   Console::Write( "Substring '{0}' in ' {1}' is ", str1->Substring( 2, 2 ), str1 );
   Console::Write( " {0} ", str );
   Console::WriteLine( "substring '{0}' in ' {1}'.", str2->Substring( 0, 2 ), str2 );
}

/*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*/

String str1 = "machine";
String str2 = "device";
String str;
int result;

Console.WriteLine();
Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2);
result = String.Compare(str1, 2, str2, 0, 2);
str = ((result < 0) ? "less than" : ((result > 0) ? "greater than" : "equal to"));
Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1);
Console.Write("{0} ", str);
Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(0, 2), str2);

/*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*/

open System

let str1 = "machine"
let str2 = "device"

printfn "\nstr1 = '{str1}', str2 = '{str2}'"

let result = String.Compare(str1, 2, str2, 0, 2)
let str = 
    if result < 0 then "less than" 
    elif result > 0 then "greater than" 
    else "equal to"

printf $"Substring '{str1.Substring(2, 2)}' in '{str1}' is "
printf $"{str} "
printfn $"substring '{str2.Substring(0, 2)}' in '{str2}'."

(*
This example produces the following results:

str1 = 'machine', str2 = 'device'
Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
*)

' Sample for String.Compare(String, Int32, String, Int32, Int32)
Class Sample
   Public Shared Sub Main()
      '                       0123456
      Dim str1 As [String] = "machine"
      Dim str2 As [String] = "device"
      Dim str As [String]
      Dim result As Integer
      
      Console.WriteLine()
      Console.WriteLine("str1 = '{0}', str2 = '{1}'", str1, str2)
      result = [String].Compare(str1, 2, str2, 0, 2)
      str = IIf(result < 0, "less than", IIf(result > 0, "greater than", "equal to"))
      Console.Write("Substring '{0}' in '{1}' is ", str1.Substring(2, 2), str1)
      Console.Write("{0} ", str)
      Console.WriteLine("substring '{0}' in '{1}'.", str2.Substring(0, 2), str2)
   End Sub
End Class
'
'This example produces the following results:
'
'str1 = 'machine', str2 = 'device'
'Substring 'ch' in 'machine' is less than substring 'de' in 'device'.
'

Remarks

The substrings to compare start in strA at indexA and in strB at indexB. Both indexA and indexB are zero-based; that is, the first character in strA and strB is at position zero. The length of the first substring is equal to the length of strA minus indexA plus one. The length of the second substring is equal to the length of strB minus indexB plus one.

The number of characters to compare is the lesser of the lengths of the two substrings, and length. The indexA, indexB, and length parameters must be nonnegative.

The comparison is performed using word sort rules. For more information about word, string, and ordinal sorts, see System.Globalization.CompareOptions.

Warning

One or both comparands can be null. By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.

The comparison terminates when an inequality is discovered or both substrings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, then the string with remaining characters is considered greater. The return value is the result of the last comparison performed.

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, true) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Notes to Callers

Character sets include ignorable characters. The Compare(String, Int32, String, Int32, Int32) method does not consider these characters when it performs a linguistic or culture-sensitive comparison. To recognize ignorable characters in your comparison, call the Compare(String, Int32, String, Int32, Int32, StringComparison) method and supply a value of Ordinal or OrdinalIgnoreCase for the comparisonType parameter.

Applies to

Compare(String, String, CultureInfo, CompareOptions)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares two specified String objects using the specified comparison options and culture-specific information to influence the comparison, and returns an integer that indicates the relationship of the two strings to each other in the sort order.

public:
 static int Compare(System::String ^ strA, System::String ^ strB, System::Globalization::CultureInfo ^ culture, System::Globalization::CompareOptions options);

public static int Compare (string? strA, string? strB, System.Globalization.CultureInfo? culture, System.Globalization.CompareOptions options);

public static int Compare (string strA, string strB, System.Globalization.CultureInfo culture, System.Globalization.CompareOptions options);

static member Compare : string * string * System.Globalization.CultureInfo * System.Globalization.CompareOptions -> int

Public Shared Function Compare (strA As String, strB As String, culture As CultureInfo, options As CompareOptions) As Integer

Parameters

strA: String

The first string to compare.

strB: String

The second string to compare.

culture: CultureInfo

The culture that supplies culture-specific comparison information. If culture is null, the current culture is used.

options: CompareOptions

Options to use when performing the comparison (such as ignoring case or symbols).

Returns

Int32

A 32-bit signed integer that indicates the lexical relationship between strA and strB, as shown in the following table

Value	Condition
Less than zero	`strA` precedes `strB` in the sort order.
Zero	`strA` occurs in the same position as `strB` in the sort order.
Greater than zero	`strA` follows `strB` in the sort order.

Exceptions

ArgumentException

options is not a CompareOptions value.

Examples

The following example compares two strings in three different ways: Use linguistic comparison for the en-US culture; using linguistic case-sensitive comparison for the en-US culture; and using an ordinal comparison. It illustrates how the three methods of comparison produce three different results.

using namespace System;
using namespace System::Globalization;

public ref class Example
{
public:
   static void Main()
   {
      String^ string1 = "brother";
      String^ string2 = "Brother";
      String^ relation;
      int result;

      // Cultural (linguistic) comparison.
      result = String::Compare(string1, string2, gcnew CultureInfo("en-US"),
                              CompareOptions::None);
      if (result > 0)
         relation = "comes after";
      else if (result == 0)
         relation = "is the same as";
      else
         relation = "comes before";

      Console::WriteLine("'{0}' {1} '{2}'.",
                        string1, relation, string2);

      // Cultural (linguistic) case-insensitive comparison.
      result = String::Compare(string1, string2, gcnew CultureInfo("en-US"),
                              CompareOptions::IgnoreCase);
      if (result > 0)
         relation = "comes after";
      else if (result == 0)
         relation = "is the same as";
      else
         relation = "comes before";

      Console::WriteLine("'{0}' {1} '{2}'.",
                        string1, relation, string2);

       // Culture-insensitive ordinal comparison.
      result = String::CompareOrdinal(string1, string2);
      if (result > 0)
         relation = "comes after";
      else if (result == 0)
         relation = "is the same as";
      else
         relation = "comes before";

      Console::WriteLine("'{0}' {1} '{2}'.",
                        string1, relation, string2);
   }
};

int main()
{
    Example::Main();
}


// The example produces the following output:
//    'brother' comes before 'Brother'.
//    'brother' is the same as 'Brother'.
//    'brother' comes after 'Brother'.

using System;
using System.Globalization;

public class Example0
{
    public static void Main()
    {
        string string1 = "brother";
        string string2 = "Brother";
        string relation;
        int result;

        // Cultural (linguistic) comparison.
        result = String.Compare(string1, string2, new CultureInfo("en-US"), 
                              CompareOptions.None);
        if (result > 0)
            relation = "comes after";
        else if (result == 0)
            relation = "is the same as";
        else
            relation = "comes before";

        Console.WriteLine("'{0}' {1} '{2}'.", 
                        string1, relation, string2);

        // Cultural (linguistic) case-insensitive comparison.
        result = String.Compare(string1, string2, new CultureInfo("en-US"), 
                              CompareOptions.IgnoreCase);
        if (result > 0)
            relation = "comes after";
        else if (result == 0)
            relation = "is the same as";
        else
            relation = "comes before";

        Console.WriteLine("'{0}' {1} '{2}'.", 
                        string1, relation, string2);
 
        // Culture-insensitive ordinal comparison.
        result = String.CompareOrdinal(string1, string2);
        if (result > 0)
            relation = "comes after";
        else if (result == 0)
            relation = "is the same as";
        else
            relation = "comes before";

        Console.WriteLine("'{0}' {1} '{2}'.", 
                        string1, relation, string2);

        // The example produces the following output:
        //    'brother' comes before 'Brother'.   
        //    'brother' is the same as 'Brother'.
        //    'brother' comes after 'Brother'.
    }
}

open System
open System.Globalization

let string1 = "brother"
let string2 = "Brother"

// Cultural (linguistic) comparison.
let result = String.Compare(string1, string2, CultureInfo "en-US", CompareOptions.None)
let relation =
    if result > 0 then "comes after"
    elif result = 0 then "is the same as"
    else "comes before"

printfn $"'{string1}' {relation} '{string2}'."

// Cultural (linguistic) case-insensitive comparison.
let result2 = String.Compare(string1, string2, CultureInfo "en-US", CompareOptions.IgnoreCase)
let relation2 =
    if result2 > 0 then "comes after"
    elif result2 = 0 then "is the same as"
    else "comes before"

printfn $"'{string1}' {relation2} '{string2}'."

// Culture-insensitive ordinal comparison.
let result3 = String.CompareOrdinal(string1, string2)
let relation3 =
    if result2 > 0 then "comes after"
    elif result2 = 0 then "is the same as"
    else "comes before"

printfn $"'{string1}' {relation} '{string2}'."

// The example produces the following output:
//    'brother' comes before 'Brother'.   
//    'brother' is the same as 'Brother'.
//    'brother' comes after 'Brother'.

Imports System.Globalization

Public Module Example
   Public Sub Main()
      Dim string1 As String = "brother"
      Dim string2 As String = "Brother"
      Dim relation As String
      Dim result As Integer

      ' Cultural (linguistic) comparison.
      result = String.Compare(string1, string2, _
                              New CultureInfo("en-US"), CompareOptions.None)
      If result > 0 Then
         relation = "comes after"
      ElseIf result = 0 Then
         relation = "is the same as"
      Else
         relation = "comes before"
      End If
      Console.WriteLine("'{0}' {1} '{2}'.", string1, relation, string2)

      ' Cultural (linguistic) case-insensitive comparison.
      result = String.Compare(string1, string2, _
                              New CultureInfo("en-US"), CompareOptions.IgnoreCase)
      If result > 0 Then
         relation = "comes after"
      ElseIf result = 0 Then
         relation = "is the same as"
      Else
         relation = "comes before"
      End If
      Console.WriteLine("'{0}' {1} '{2}'.", string1, relation, string2)

      ' Culture-insensitive ordinal comparison.
      result = String.CompareOrdinal(string1, string2)
      If result > 0 Then
         relation = "comes after"
      ElseIf result = 0 Then
         relation = "is the same as"
      Else
         relation = "comes before"
      End If
      Console.WriteLine("'{0}' {1} '{2}'.", string1, relation, string2)
   End Sub
End Module
' The example produces the following output:
'    'brother' comes before 'Brother'.   
'    'brother' is the same as 'Brother'.
'    'brother' comes after 'Brother'.

Remarks

Caution

The Compare(String, String, CultureInfo, CompareOptions) method is designed primarily for use in sorting or alphabetizing operations. It should not be used when the primary purpose of the method call is to determine whether two strings are equivalent (that is, when the purpose of the method call is to test for a return value of zero). To determine whether two strings are equivalent, call the Equals method.

The comparison can be further specified by the options parameter, which consists of one or more members of the CompareOptions enumeration. However, because the purpose of this method is to conduct a culture-sensitive string comparison, the CompareOptions.Ordinal and CompareOptions.OrdinalIgnoreCase values have no effect.

Either or both comparands can be null. By definition, any string, including String.Empty, compares greater than a null reference, and two null references compare equal to each other.

The comparison terminates when an inequality is discovered or both strings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, the string with the remaining characters is considered greater.

Notes to Callers

Character sets include ignorable characters, which are characters that are not considered when performing a linguistic or culture-sensitive comparison. The Compare(String, String, CultureInfo, CompareOptions) method does not consider such characters when it performs a culture-sensitive comparison. To recognize ignorable characters in your comparison, supply a value of Ordinal or OrdinalIgnoreCase for the options parameter.

Applies to

Compare(String, String, Boolean, CultureInfo)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares two specified String objects, ignoring or honoring their case, and using culture-specific information to influence the comparison, and returns an integer that indicates their relative position in the sort order.

public:
 static int Compare(System::String ^ strA, System::String ^ strB, bool ignoreCase, System::Globalization::CultureInfo ^ culture);

public static int Compare (string? strA, string? strB, bool ignoreCase, System.Globalization.CultureInfo? culture);

public static int Compare (string strA, string strB, bool ignoreCase, System.Globalization.CultureInfo culture);

static member Compare : string * string * bool * System.Globalization.CultureInfo -> int

Public Shared Function Compare (strA As String, strB As String, ignoreCase As Boolean, culture As CultureInfo) As Integer

Parameters

strA: String

The first string to compare.

strB: String

The second string to compare.

ignoreCase: Boolean

true to ignore case during the comparison; otherwise, false.

culture: CultureInfo

An object that supplies culture-specific comparison information. If culture is null, the current culture is used.

Returns

Int32

A 32-bit signed integer that indicates the lexical relationship between the two comparands.

Value	Condition
Less than zero	`strA` precedes `strB` in the sort order.
Zero	`strA` occurs in the same position as `strB` in the sort order.
Greater than zero	`strA` follows `strB` in the sort order.

Examples

The following example demonstrates how culture can affect a comparison. In Czech - Czech Republic culture, "ch" is a single character that is greater than "d". However, in English - United States culture, "ch" consists of two characters, and "c" is less than "d".

using namespace System;
using namespace System::Globalization;
String^ symbol( int r )
{
   String^ s = "=";
   if ( r < 0 )
      s = "<";
   else
   if ( r > 0 )
      s = ">";


   return s;
}

int main()
{
   String^ str1 = "change";
   String^ str2 = "dollar";
   String^ relation = nullptr;
   relation = symbol( String::Compare( str1, str2, false, gcnew CultureInfo( "en-US" ) ) );
   Console::WriteLine( "For en-US: {0} {1} {2}", str1, relation, str2 );
   relation = symbol( String::Compare( str1, str2, false, gcnew CultureInfo( "cs-CZ" ) ) );
   Console::WriteLine( "For cs-CZ: {0} {1} {2}", str1, relation, str2 );
}

/*
This example produces the following results.
For en-US: change < dollar
For cs-CZ: change > dollar
*/

public static void Main()
{
    String str1 = "change";
    String str2 = "dollar";
    String relation;

    relation = symbol(String.Compare(str1, str2, false, new CultureInfo("en-US")));
    Console.WriteLine("For en-US: {0} {1} {2}", str1, relation, str2);

    relation = symbol(String.Compare(str1, str2, false, new CultureInfo("cs-CZ")));
    Console.WriteLine("For cs-CZ: {0} {1} {2}", str1, relation, str2);
}

private static String symbol(int r)
{
    String s = "=";
    if (r < 0) s = "<";
    else if (r > 0) s = ">";
    return s;
}

/*
This example produces the following results.
For en-US: change < dollar
For cs-CZ: change > dollar
*/

let symbol r =
    if r < 0 then "<"
    elif r > 0 then ">"
    else "="

let str1 = "change"
let str2 = "dollar"

let relation1 = 
    String.Compare(str1, str2, false, CultureInfo "en-US")
    |> symbol
printfn $"For en-US: {str1} {relation1} {str2}"

let relation2 = 
    String.Compare(str1, str2, false, CultureInfo "cs-CZ")
    |> symbol
printfn $"For cs-CZ: {str1} {relation2} {str2}"

(*
This example produces the following results.
For en-US: change < dollar
For cs-CZ: change > dollar
*)

Imports System.Globalization
 _

Class Sample
   Public Shared Sub Main()
      Dim str1 As [String] = "change"
      Dim str2 As [String] = "dollar"
      Dim relation As [String] = Nothing
      
      relation = symbol([String].Compare(str1, str2, False, New CultureInfo("en-US")))
      Console.WriteLine("For en-US: {0} {1} {2}", str1, relation, str2)
      
      relation = symbol([String].Compare(str1, str2, False, New CultureInfo("cs-CZ")))
      Console.WriteLine("For cs-CZ: {0} {1} {2}", str1, relation, str2)
   End Sub
   
   Private Shared Function symbol(r As Integer) As [String]
      Dim s As [String] = "="
      If r < 0 Then
         s = "<"
      Else
         If r > 0 Then
            s = ">"
         End If
      End If
      Return s
   End Function 'symbol
End Class
'
'This example produces the following results.
'For en-US: change < dollar
'For cs-CZ: change > dollar
'

Remarks

The comparison is performed using word sort rules. For more information about word, string, and ordinal sorts, see System.Globalization.CompareOptions.

One or both comparands can be null. By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.

The comparison terminates when an inequality is discovered or both strings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, then the string with remaining characters is considered greater. The return value is the result of the last comparison performed.

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, true) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Notes to Callers

Character sets include ignorable characters. The Compare(String, String, Boolean, CultureInfo) method does not consider such characters when it performs a culture-sensitive comparison. For example, if the following code is run on the .NET Framework 4 or later, a case-insensitive comparison of "animal" with "Ani-mal" (using a soft hyphen, or U+00AD) using the invariant culture indicates that the two strings are equivalent.

  string s1 = "Ani\u00ADmal";
  string s2 = "animal";

  Console.WriteLine("Comparison of '{0}' and '{1}': {2}", 
                  s1, s2, String.Compare(s1, s2, true,
                  CultureInfo.InvariantCulture));

  // The example displays the following output:
  //       Comparison of 'Ani-mal' and 'animal': 0

open System
open System.Globalization

let s1 = "Ani\u00ADmal"
let s2 = "animal"

printfn $"Comparison of '{s1}' and '{s2}': {String.Compare(s1, s2, true, CultureInfo.InvariantCulture)}"

// The example displays the following output:
//       Comparison of 'Ani-mal' and 'animal': 0

Imports System.Globalization

Module Example
   Public Sub Main()
      Dim s1 As String = "Ani" + ChrW(&h00AD) + "mal"
      Dim s2 As String = "animal"
      
      Console.WriteLine("Comparison of '{0}' and '{1}': {2}", 
                        s1, s2, String.Compare(s1, s2, True,
                        CultureInfo.InvariantCulture))
  End Sub
End Module
' The example displays the following output:
'       Comparison of 'ani-mal' and 'animal': 0

To recognize ignorable characters in a string comparison, call the Compare(String, String, CultureInfo, CompareOptions) method and supply a value of either Ordinal or OrdinalIgnoreCase for the options parameter.

Applies to

Compare(String, String, StringComparison)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares two specified String objects using the specified rules, and returns an integer that indicates their relative position in the sort order.

public:
 static int Compare(System::String ^ strA, System::String ^ strB, StringComparison comparisonType);

public static int Compare (string strA, string strB, StringComparison comparisonType);

public static int Compare (string? strA, string? strB, StringComparison comparisonType);

static member Compare : string * string * StringComparison -> int

Public Shared Function Compare (strA As String, strB As String, comparisonType As StringComparison) As Integer

Parameters

strA: String

The first string to compare.

strB: String

The second string to compare.

comparisonType: StringComparison

One of the enumeration values that specifies the rules to use in the comparison.

Returns

Int32

A 32-bit signed integer that indicates the lexical relationship between the two comparands.

Value	Condition
Less than zero	`strA` precedes `strB` in the sort order.
Zero	`strA` is in the same position as `strB` in the sort order.
Greater than zero	`strA` follows `strB` in the sort order.

Exceptions

ArgumentException

comparisonType is not a StringComparison value.

NotSupportedException

StringComparison is not supported.

Examples

The following example compares three versions of the letter "I". The results are affected by the choice of culture, whether case is ignored, and whether an ordinal comparison is performed.

// This example demonstrates the
// System.String.Compare(String, String, StringComparison) method.

using namespace System;
using namespace System::Threading;

void Test(int testStringIndex, int searchStringIndex, 
          StringComparison comparison, array<String^>^ testI, 
          array<String^>^ testNames)
{
    String^ resultFormat = "{0} is {1} {2}";
    String^ resultString = "equal to";
    int comparisonValue = 0;

    comparisonValue = String::Compare(testI[testStringIndex],
        testI[searchStringIndex], comparison);
    if (comparisonValue < 0)
    {
        resultString = "less than";
    }
    else if (comparisonValue > 0)
    {
        resultString = "greater than";
    }
    Console::WriteLine(resultFormat, testNames[testStringIndex], resultString,
        testNames[searchStringIndex]);
}

int main()
{
    String^ introMessage =
        "Compare three versions of the letter I using different " +
        "values of StringComparison.";

    // Define an array of strings where each element contains a version of
    // the letter I. (An array of strings is used so you can easily modify
    // this code example to test additional or different combinations of
    // strings.)

    array<String^>^ letterVariation = gcnew array<String^>(3);
    // LATIN SMALL LETTER I (U+0069)
    letterVariation[0] = "i";
    // LATIN SMALL LETTER DOTLESS I (U+0131)
    letterVariation[1] = L"\u0131";
    // LATIN CAPITAL LETTER I (U+0049)
    letterVariation[2] = "I";

    array<String^>^ unicodeNames = {
        "LATIN SMALL LETTER I (U+0069)",
        "LATIN SMALL LETTER DOTLESS I (U+0131)",
        "LATIN CAPITAL LETTER I (U+0049)"};

    array<StringComparison>^ comparisonValues = {
        StringComparison::CurrentCulture,
        StringComparison::CurrentCultureIgnoreCase,
        StringComparison::InvariantCulture,
        StringComparison::InvariantCultureIgnoreCase,
        StringComparison::Ordinal,
        StringComparison::OrdinalIgnoreCase};

    Console::Clear();
    Console::WriteLine(introMessage);

    // Display the current culture because the culture-specific comparisons
    // can produce different results with different cultures.
    Console::WriteLine("The current culture is {0}.{1}",
        Thread::CurrentThread->CurrentCulture->Name, Environment::NewLine);

    // Determine the relative sort order of three versions of the letter I.
    for each (StringComparison stringCmp in comparisonValues)
    {
        Console::WriteLine("StringComparison.{0}:", stringCmp);

        // LATIN SMALL LETTER I (U+0069) : LATIN SMALL LETTER DOTLESS I
        // (U+0131)
        Test(0, 1, stringCmp, letterVariation, unicodeNames);

        // LATIN SMALL LETTER I (U+0069) : LATIN CAPITAL LETTER I (U+0049)
        Test(0, 2, stringCmp, letterVariation, unicodeNames);

        // LATIN SMALL LETTER DOTLESS I (U+0131) : LATIN CAPITAL LETTER I
        // (U+0049)
        Test(1, 2, stringCmp, letterVariation, unicodeNames);

        Console::WriteLine();
    }
}

/*
This code example produces the following results:

Compare three versions of the letter I using different values of 
StringComparison.
The current culture is en-US.

StringComparison.CurrentCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.CurrentCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.InvariantCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.InvariantCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.Ordinal:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is greater than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

StringComparison.OrdinalIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER 
  DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN 
  CAPITAL LETTER I (U+0049)

*/

// This example demonstrates the 
// System.String.Compare(String, String, StringComparison) method.

using System;
using System.Threading;

class Sample 
{
    public static void Main() 
    {
        string intro = "Compare three versions of the letter I using different " + 
                       "values of StringComparison.";

        // Define an array of strings where each element contains a version of the 
        // letter I. (An array of strings is used so you can easily modify this 
        // code example to test additional or different combinations of strings.)  

        string[] threeIs = new string[3];
        // LATIN SMALL LETTER I (U+0069)
        threeIs[0] = "\u0069";
        // LATIN SMALL LETTER DOTLESS I (U+0131)
        threeIs[1] = "\u0131";
        // LATIN CAPITAL LETTER I (U+0049)
        threeIs[2] = "\u0049";

        string[] unicodeNames = 
        {
            "LATIN SMALL LETTER I (U+0069)", 
            "LATIN SMALL LETTER DOTLESS I (U+0131)", 
            "LATIN CAPITAL LETTER I (U+0049)"
        };

        StringComparison[] scValues =
        {
            StringComparison.CurrentCulture,
            StringComparison.CurrentCultureIgnoreCase,
            StringComparison.InvariantCulture,
            StringComparison.InvariantCultureIgnoreCase,
            StringComparison.Ordinal,
            StringComparison.OrdinalIgnoreCase
        };

        Console.Clear();
        Console.WriteLine(intro);

        // Display the current culture because the culture-specific comparisons
        // can produce different results with different cultures.
        Console.WriteLine(
            "The current culture is {0}.\n", Thread.CurrentThread.CurrentCulture.Name);

        // Determine the relative sort order of three versions of the letter I. 
        foreach (StringComparison sc in scValues)
        {
            Console.WriteLine("StringComparison.{0}:", sc);

            // LATIN SMALL LETTER I (U+0069) : LATIN SMALL LETTER DOTLESS I (U+0131)
            Test(0, 1, sc, threeIs, unicodeNames);

            // LATIN SMALL LETTER I (U+0069) : LATIN CAPITAL LETTER I (U+0049)
            Test(0, 2, sc, threeIs, unicodeNames);

            // LATIN SMALL LETTER DOTLESS I (U+0131) : LATIN CAPITAL LETTER I (U+0049)
            Test(1, 2, sc, threeIs, unicodeNames);

            Console.WriteLine();
        }
    }

    protected static void Test(
        int x, int y, StringComparison comparison, string[] testI, string[] testNames)
    {
        string resultFmt = "{0} is {1} {2}";
        string result = "equal to";
        int cmpValue = 0;

        cmpValue = String.Compare(testI[x], testI[y], comparison);
        if (cmpValue < 0)
            result = "less than";
        else if (cmpValue > 0)
            result = "greater than";
        Console.WriteLine(resultFmt, testNames[x], result, testNames[y]);
    }
}

/*
This code example produces the following results:

Compare three versions of the letter I using different values of StringComparison.
The current culture is en-US.

StringComparison.CurrentCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.CurrentCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.InvariantCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.InvariantCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.Ordinal:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is greater than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.OrdinalIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

*/

// This example demonstrates the 
// System.String.Compare(String, String, StringComparison) method.

open System
open System.Threading

let test x y (comparison: StringComparison) (testI: string[]) (testNames: string[]) =
    let cmpValue = String.Compare(testI[x], testI[y], comparison)
    let result =
        if cmpValue < 0 then
            "less than"
        elif cmpValue > 0 then
            "greater than"
        else
            "equal to"
    printfn $"{testNames[x]} is {result} {testNames[y]}"

let intro = "Compare three versions of the letter I using different values of StringComparison."

// Define an array of strings where each element contains a version of the 
// letter I. (An array of strings is used so you can easily modify this 
// code example to test additional or different combinations of strings.)  

let threeIs = 
  [|// LATIN SMALL LETTER I (U+0069)
    "\u0069"
    // LATIN SMALL LETTER DOTLESS I (U+0131)
    "\u0131"
    // LATIN CAPITAL LETTER I (U+0049)
    "\u0049" |]

let unicodeNames =
    [| "LATIN SMALL LETTER I (U+0069)"
       "LATIN SMALL LETTER DOTLESS I (U+0131)"
       "LATIN CAPITAL LETTER I (U+0049)" |]

let scValues =
    [| StringComparison.CurrentCulture
       StringComparison.CurrentCultureIgnoreCase
       StringComparison.InvariantCulture
       StringComparison.InvariantCultureIgnoreCase
       StringComparison.Ordinal
       StringComparison.OrdinalIgnoreCase |]

Console.Clear()
printfn $"{intro}"

// Display the current culture because the culture-specific comparisons
// can produce different results with different cultures.
printfn $"The current culture is {Thread.CurrentThread.CurrentCulture.Name}.\n"

// Determine the relative sort order of three versions of the letter I. 
for sc in scValues do
    printfn $"StringComparison.{sc}:"

    // LATIN SMALL LETTER I (U+0069) : LATIN SMALL LETTER DOTLESS I (U+0131)
    test 0 1 sc threeIs unicodeNames

    // LATIN SMALL LETTER I (U+0069) : LATIN CAPITAL LETTER I (U+0049)
    test 0 2 sc threeIs unicodeNames

    // LATIN SMALL LETTER DOTLESS I (U+0131) : LATIN CAPITAL LETTER I (U+0049)
    test 1 2 sc threeIs unicodeNames

    printfn ""

(*
This code example produces the following results:

Compare three versions of the letter I using different values of StringComparison.
The current culture is en-US.

StringComparison.CurrentCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.CurrentCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.InvariantCulture:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.InvariantCultureIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.Ordinal:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is greater than LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)

StringComparison.OrdinalIgnoreCase:
LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
*)

' This example demonstrates the 
' System.String.Compare(String, String, StringComparison) method.

Imports System.Threading

Class Sample
    Public Shared Sub Main() 
        Dim intro As String = "Compare three versions of the letter I using different " & _
                              "values of StringComparison."
        
        ' Define an array of strings where each element contains a version of the 
        ' letter I. (An array of strings is used so you can easily modify this 
        ' code example to test additional or different combinations of strings.)  
        Dim threeIs(2) As String
        ' LATIN SMALL LETTER I (U+0069)
        threeIs(0) = "i"
        ' LATIN SMALL LETTER DOTLESS I (U+0131)
        threeIs(1) = "ı"
        ' LATIN CAPITAL LETTER I (U+0049)
        threeIs(2) = "I"
        
        Dim unicodeNames As String() =  { _
                            "LATIN SMALL LETTER I (U+0069)", _
                            "LATIN SMALL LETTER DOTLESS I (U+0131)", _
                            "LATIN CAPITAL LETTER I (U+0049)" }
        
        Dim scValues As StringComparison() =  { _
                            StringComparison.CurrentCulture, _
                            StringComparison.CurrentCultureIgnoreCase, _
                            StringComparison.InvariantCulture, _
                            StringComparison.InvariantCultureIgnoreCase, _
                            StringComparison.Ordinal, _
                            StringComparison.OrdinalIgnoreCase }
        '
        Console.Clear()
        Console.WriteLine(intro)
        
        ' Display the current culture because the culture-specific comparisons
        ' can produce different results with different cultures.
        Console.WriteLine("The current culture is {0}." & vbCrLf, _
                           Thread.CurrentThread.CurrentCulture.Name)
        
        ' Determine the relative sort order of three versions of the letter I. 
        Dim sc As StringComparison
        For Each sc In  scValues
            Console.WriteLine("StringComparison.{0}:", sc)
            
            ' LATIN SMALL LETTER I (U+0069) : LATIN SMALL LETTER DOTLESS I (U+0131)
            Test(0, 1, sc, threeIs, unicodeNames)
            
            ' LATIN SMALL LETTER I (U+0069) : LATIN CAPITAL LETTER I (U+0049)
            Test(0, 2, sc, threeIs, unicodeNames)
            
            ' LATIN SMALL LETTER DOTLESS I (U+0131) : LATIN CAPITAL LETTER I (U+0049)
            Test(1, 2, sc, threeIs, unicodeNames)
            
            Console.WriteLine()
        Next sc
    
    End Sub
    
    Protected Shared Sub Test(ByVal x As Integer, ByVal y As Integer, _
                              ByVal comparison As StringComparison, _
                              ByVal testI() As String, ByVal testNames() As String) 
        Dim resultFmt As String = "{0} is {1} {2}"
        Dim result As String = "equal to"
        Dim cmpValue As Integer = 0
        '
        cmpValue = String.Compare(testI(x), testI(y), comparison)
        If cmpValue < 0 Then
            result = "less than"
        ElseIf cmpValue > 0 Then
            result = "greater than"
        End If
        Console.WriteLine(resultFmt, testNames(x), result, testNames(y))
    
    End Sub
End Class

'
'This code example produces the following results:
'
'Compare three versions of the letter I using different values of StringComparison.
'The current culture is en-US.
'
'StringComparison.CurrentCulture:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.CurrentCultureIgnoreCase:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.InvariantCulture:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is less than LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.InvariantCultureIgnoreCase:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.Ordinal:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is greater than LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'
'StringComparison.OrdinalIgnoreCase:
'LATIN SMALL LETTER I (U+0069) is less than LATIN SMALL LETTER DOTLESS I (U+0131)
'LATIN SMALL LETTER I (U+0069) is equal to LATIN CAPITAL LETTER I (U+0049)
'LATIN SMALL LETTER DOTLESS I (U+0131) is greater than LATIN CAPITAL LETTER I (U+0049)
'

Remarks

One or both comparands can be null. By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, true) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Notes to Callers

Character sets include ignorable characters. The Compare(String, String, StringComparison) method does not consider such characters when it performs a culture-sensitive comparison. To recognize ignorable characters in your comparison, supply a value of Ordinal or OrdinalIgnoreCase for the comparisonType parameter.

Applies to

Compare(String, String, Boolean)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares two specified String objects, ignoring or honoring their case, and returns an integer that indicates their relative position in the sort order.

public:
 static int Compare(System::String ^ strA, System::String ^ strB, bool ignoreCase);

public static int Compare (string strA, string strB, bool ignoreCase);

public static int Compare (string? strA, string? strB, bool ignoreCase);

static member Compare : string * string * bool -> int

Public Shared Function Compare (strA As String, strB As String, ignoreCase As Boolean) As Integer

Parameters

strA: String

The first string to compare.

strB: String

The second string to compare.

ignoreCase: Boolean

true to ignore case during the comparison; otherwise, false.

Returns

Int32

A 32-bit signed integer that indicates the lexical relationship between the two comparands.

Value	Condition
Less than zero	`strA` precedes `strB` in the sort order.
Zero	`strA` occurs in the same position as `strB` in the sort order.
Greater than zero	`strA` follows `strB` in the sort order.

Examples

The following example demonstrates that the Compare(String, String, Boolean) method is equivalent to using ToUpper or ToLower when comparing strings.

using namespace System;

void main()
{
   // Create upper-case characters from their Unicode code units.
   String^ stringUpper = "\x0041\x0042\x0043";

   // Create lower-case characters from their Unicode code units.
   String^ stringLower = "\x0061\x0062\x0063";

   // Display the strings.
   Console::WriteLine("Comparing '{0}' and '{1}':", 
                      stringUpper, stringLower);

   // Compare the uppercased strings; the result is true.
   Console::WriteLine("The Strings are equal when capitalized? {0}",
                      String::Compare(stringUpper->ToUpper(), stringLower->ToUpper()) == 0 
                                      ? "true" : "false");

   // The previous method call is equivalent to this Compare method, which ignores case.
   Console::WriteLine("The Strings are equal when case is ignored? {0}",
                      String::Compare(stringUpper, stringLower, true) == 0
                                      ? "true" : "false");
}
// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true

// Create upper-case characters from their Unicode code units.
String stringUpper = "\x0041\x0042\x0043";

// Create lower-case characters from their Unicode code units.
String stringLower = "\x0061\x0062\x0063";

// Display the strings.
Console.WriteLine("Comparing '{0}' and '{1}':", 
                stringUpper, stringLower);

// Compare the uppercased strings; the result is true.
Console.WriteLine("The Strings are equal when capitalized? {0}",
                String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) == 0 
                               ? "true" : "false");

// The previous method call is equivalent to this Compare method, which ignores case.
Console.WriteLine("The Strings are equal when case is ignored? {0}",
                String.Compare(stringUpper, stringLower, true) == 0
                               ? "true" : "false" );

// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true

open System

// Create upper-case characters from their Unicode code units.
let stringUpper = "\x0041\x0042\x0043"

// Create lower-case characters from their Unicode code units.
let stringLower = "\x0061\x0062\x0063"

// Display the strings.
printfn $"Comparing '{stringUpper}' and '{stringLower}':"

// Compare the uppercased strings the result is true.
printfn $"The Strings are equal when capitalized? %b{String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) = 0}"

// The previous method call is equivalent to this Compare method, which ignores case.
printfn $"The Strings are equal when case is ignored? %b{String.Compare(stringUpper, stringLower, true) = 0}"

// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true

Public Module Example
   Public Sub Main()
      ' Create upper-case characters from their Unicode code units.
      Dim stringUpper As String = ChrW(&H41) + ChrW(&H42) + ChrW(&H43)

      ' Create lower-case characters from their Unicode code units.
      Dim stringLower As String = ChrW(&H61) + ChrW(&H62) + ChrW(&H63)

      ' Display the strings.
      Console.WriteLine("Comparing '{0}' and '{1}':", 
                        stringUpper, stringLower)

      ' Compare the uppercased strings; the result is true.
      Console.WriteLine("The Strings are equal when capitalized? {0}",
                        If(String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) = 0, 
                                          "true", "false"))

      ' The previous method call is equivalent to this Compare method, which ignores case.
      Console.WriteLine("The Strings are equal when case is ignored? {0}",
                        If(String.Compare(stringUpper, stringLower, true) = 0,
                                          "true", "false"))
   End Sub
End Module 
' The example displays the following output:
'       Comparing 'ABC' and 'abc':
'       The Strings are equal when capitalized? true
'       The Strings are equal when case is ignored? true

Remarks

The comparison is performed using word sort rules. For more information about word, string, and ordinal sorts, see System.Globalization.CompareOptions.

Warning

When comparing strings, you should call the Compare(String, String, StringComparison) method, which requires that you explicitly specify the type of string comparison that the method uses. For more information, see Best Practices for Using Strings.

One or both comparands can be null. By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.

The comparison terminates when an inequality is discovered or both strings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, then the string with remaining characters is considered greater. The return value is the result of the last comparison performed.

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, true) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Notes to Callers

Character sets include ignorable characters. The Compare(String, String, Boolean) method does not consider such characters when it performs a culture-sensitive comparison. For example, a culture-sensitive, case-insensitive comparison of "animal" with "Ani-mal" (using a soft hyphen, or U+00AD) indicates that the two strings are equivalent.

string s1 = "Ani\u00ADmal";
string s2 = "animal";

Console.WriteLine("Comparison of '{0}' and '{1}': {2}",
                s1, s2, String.Compare(s1, s2, true));

// The example displays the following output:
//       Comparison of 'Ani-mal' and 'animal': 0

open System

let s1 = "Ani\u00ADmal"
let s2 = "animal"

printfn $"Comparison of '{s1}' and '{s2}': {String.Compare(s1, s2, true)}"

// The example displays the following output:
//       Comparison of 'Ani-mal' and 'animal': 0

Module Example
   Public Sub Main()
      Dim s1 As String = "Ani" + ChrW(&h00AD) + "mal"
      Dim s2 As String = "animal"
      
      Console.WriteLine("Comparison of '{0}' and '{1}': {2}", 
                        s1, s2, String.Compare(s1, s2, True))
  End Sub
End Module
' The example displays the following output:
'       Comparison of 'ani-mal' and 'animal': 0

To recognize ignorable characters in a string comparison, call the Compare(String, String, StringComparison) method and supply a value of either Ordinal or OrdinalIgnoreCase for the comparisonType parameter.

Applies to

Compare(String, String)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Compares two specified String objects and returns an integer that indicates their relative position in the sort order.

public:
 static int Compare(System::String ^ strA, System::String ^ strB);

public static int Compare (string strA, string strB);

public static int Compare (string? strA, string? strB);

static member Compare : string * string -> int

Public Shared Function Compare (strA As String, strB As String) As Integer

Parameters

strA: String

The first string to compare.

strB: String

The second string to compare.

Returns

Int32

A 32-bit signed integer that indicates the lexical relationship between the two comparands.

Value	Condition
Less than zero	`strA` precedes `strB` in the sort order.
Zero	`strA` occurs in the same position as `strB` in the sort order.
Greater than zero	`strA` follows `strB` in the sort order.

Examples

The following example calls the Compare(String, String) method to compare three sets of strings.

using namespace System;

void main()
{
   // Create upper-case characters from their Unicode code units.
   String^ stringUpper = "\x0041\x0042\x0043";

   // Create lower-case characters from their Unicode code units.
   String^ stringLower = "\x0061\x0062\x0063";

   // Display the strings.
   Console::WriteLine("Comparing '{0}' and '{1}':", 
                      stringUpper, stringLower);

   // Compare the uppercased strings; the result is true.
   Console::WriteLine("The Strings are equal when capitalized? {0}",
                      String::Compare(stringUpper->ToUpper(), stringLower->ToUpper()) == 0 
                                      ? "true" : "false");

   // The previous method call is equivalent to this Compare method, which ignores case.
   Console::WriteLine("The Strings are equal when case is ignored? {0}",
                      String::Compare(stringUpper, stringLower, true) == 0
                                      ? "true" : "false");
}
// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true

// Create upper-case characters from their Unicode code units.
String stringUpper = "\x0041\x0042\x0043";

// Create lower-case characters from their Unicode code units.
String stringLower = "\x0061\x0062\x0063";

// Display the strings.
Console.WriteLine("Comparing '{0}' and '{1}':", 
                stringUpper, stringLower);

// Compare the uppercased strings; the result is true.
Console.WriteLine("The Strings are equal when capitalized? {0}",
                String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) == 0 
                               ? "true" : "false");

// The previous method call is equivalent to this Compare method, which ignores case.
Console.WriteLine("The Strings are equal when case is ignored? {0}",
                String.Compare(stringUpper, stringLower, true) == 0
                               ? "true" : "false" );

// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true

open System

// Create upper-case characters from their Unicode code units.
let stringUpper = "\x0041\x0042\x0043"

// Create lower-case characters from their Unicode code units.
let stringLower = "\x0061\x0062\x0063"

// Display the strings.
printfn $"Comparing '{stringUpper}' and '{stringLower}':"

// Compare the uppercased strings the result is true.
printfn $"The Strings are equal when capitalized? %b{String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) = 0}"

// The previous method call is equivalent to this Compare method, which ignores case.
printfn $"The Strings are equal when case is ignored? %b{String.Compare(stringUpper, stringLower, true) = 0}"

// The example displays the following output:
//       Comparing 'ABC' and 'abc':
//       The Strings are equal when capitalized? true
//       The Strings are equal when case is ignored? true

Public Module Example
   Public Sub Main()
      ' Create upper-case characters from their Unicode code units.
      Dim stringUpper As String = ChrW(&H41) + ChrW(&H42) + ChrW(&H43)

      ' Create lower-case characters from their Unicode code units.
      Dim stringLower As String = ChrW(&H61) + ChrW(&H62) + ChrW(&H63)

      ' Display the strings.
      Console.WriteLine("Comparing '{0}' and '{1}':", 
                        stringUpper, stringLower)

      ' Compare the uppercased strings; the result is true.
      Console.WriteLine("The Strings are equal when capitalized? {0}",
                        If(String.Compare(stringUpper.ToUpper(), stringLower.ToUpper()) = 0, 
                                          "true", "false"))

      ' The previous method call is equivalent to this Compare method, which ignores case.
      Console.WriteLine("The Strings are equal when case is ignored? {0}",
                        If(String.Compare(stringUpper, stringLower, true) = 0,
                                          "true", "false"))
   End Sub
End Module 
' The example displays the following output:
'       Comparing 'ABC' and 'abc':
'       The Strings are equal when capitalized? true
'       The Strings are equal when case is ignored? true

In the following example, the ReverseStringComparer class demonstrates how you can evaluate two strings with the Compare method.

using namespace System;
using namespace System::Text;
using namespace System::Collections;

ref class ReverseStringComparer: public IComparer
{
public:
   virtual int Compare( Object^ x, Object^ y )
   {
      String^ s1 = dynamic_cast<String^>(x);
      String^ s2 = dynamic_cast<String^>(y);

      //negate the return value to get the reverse order
      return  -String::Compare( s1, s2 );
   }

};

void PrintValues( String^ title, IEnumerable^ myList )
{
   Console::Write( "{0,10}: ", title );
   StringBuilder^ sb = gcnew StringBuilder;
   {
      IEnumerator^ en = myList->GetEnumerator();
      String^ s;
      while ( en->MoveNext() )
      {
         s = en->Current->ToString();
         sb->AppendFormat(  "{0}, ", s );
      }
   }
   sb->Remove( sb->Length - 2, 2 );
   Console::WriteLine( sb );
}

void main()
{
   // Creates and initializes a new ArrayList.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "Eric" );
   myAL->Add( "Mark" );
   myAL->Add( "Lance" );
   myAL->Add( "Rob" );
   myAL->Add( "Kris" );
   myAL->Add( "Brad" );
   myAL->Add( "Kit" );
   myAL->Add( "Bradley" );
   myAL->Add( "Keith" );
   myAL->Add( "Susan" );

   // Displays the properties and values of the ArrayList.
   Console::WriteLine( "Count: {0}", myAL->Count.ToString() );

   PrintValues( "Unsorted", myAL );

   myAL->Sort();
   PrintValues( "Sorted", myAL );

   myAL->Sort( gcnew ReverseStringComparer );
   PrintValues( "Reverse", myAL );

   array<String^>^names = dynamic_cast<array<String^>^>(myAL->ToArray( String::typeid ));
}

using System;
using System.Text;
using System.Collections;

public class SamplesArrayList
{

    public static void Main()
    {
        // Creates and initializes a new ArrayList.
        ArrayList myAL = new ArrayList();
        myAL.Add("Eric");
        myAL.Add("Mark");
        myAL.Add("Lance");
        myAL.Add("Rob");
        myAL.Add("Kris");
        myAL.Add("Brad");
        myAL.Add("Kit");
        myAL.Add("Bradley");
        myAL.Add("Keith");
        myAL.Add("Susan");

        // Displays the properties and values of	the	ArrayList.
        Console.WriteLine("Count: {0}", myAL.Count);

        PrintValues("Unsorted", myAL);
        myAL.Sort();
        PrintValues("Sorted", myAL);
        myAL.Sort(new ReverseStringComparer());
        PrintValues("Reverse", myAL);

        string[] names = (string[])myAL.ToArray(typeof(string));
    }
    public static void PrintValues(string title, IEnumerable myList)
    {
        Console.Write("{0,10}: ", title);
        StringBuilder sb = new StringBuilder();
        foreach (string s in myList)
        {
            sb.AppendFormat("{0}, ", s);
        }
        sb.Remove(sb.Length - 2, 2);
        Console.WriteLine(sb);
    }
}
public class ReverseStringComparer : IComparer
{
    public int Compare(object? x, object? y)
    {
        string? s1 = x as string;
        string? s2 = y as string;
        //negate the return value to get the reverse order
        return -String.Compare(s1, s2);
    }
}

open System
open System.Text
open System.Collections.Generic

type ReverseStringComparer() =
    interface IComparer<string> with
        member _.Compare(x, y) =
            -String.Compare(x, y)

let printValues title (myList: #seq<string>) =
    printf $"{title,10}: "
    let sb = StringBuilder()
    for s in myList do
        sb.Append $"{s}, " |> ignore
    sb.Remove(sb.Length - 2, 2) |> ignore
    printfn $"{sb}"

// Creates and initializes a new ResizeArray.
let myAL = ResizeArray()
myAL.Add "Eric"
myAL.Add "Mark"
myAL.Add "Lance"
myAL.Add "Rob"
myAL.Add "Kris"
myAL.Add "Brad"
myAL.Add "Kit"
myAL.Add "Bradley"
myAL.Add "Keith"
myAL.Add "Susan"

// Displays the properties and values of	the	ArrayList.
printfn $"Count: {myAL.Count}"

printValues "Unsorted" myAL
myAL.Sort()
printValues "Sorted" myAL
myAL.Sort(ReverseStringComparer())
printValues "Reverse" myAL

Imports System.Text
Imports System.Collections



Public Class SamplesArrayList
    
    
    Public Shared Sub Main()
        Dim myAL As New ArrayList()
        ' Creates and initializes a new ArrayList.
        myAL.Add("Eric")
        myAL.Add("Mark")
        myAL.Add("Lance")
        myAL.Add("Rob")
        myAL.Add("Kris")
        myAL.Add("Brad")
        myAL.Add("Kit")
        myAL.Add("Bradley")
        myAL.Add("Keith")
        myAL.Add("Susan")
        
        ' Displays the properties and values of	the	ArrayList.
        Console.WriteLine("Count: {0}", myAL.Count)
        PrintValues("Unsorted", myAL)
        myAL.Sort()
        PrintValues("Sorted", myAL)
        Dim comp as New ReverseStringComparer
        myAL.Sort(comp)
        PrintValues("Reverse", myAL)

        Dim names As String() = CType(myAL.ToArray(GetType(String)), String())
    End Sub
   
   
    
    Public Shared Sub PrintValues(title As String, myList As IEnumerable)
        Console.Write("{0,10}: ", title)
        Dim sb As New StringBuilder()
        Dim s As String
        For Each s In  myList
            sb.AppendFormat("{0}, ", s)
        Next s
        sb.Remove(sb.Length - 2, 2)
        Console.WriteLine(sb)
    End Sub
End Class

Public Class ReverseStringComparer 
  Implements IComparer
    
     Function Compare(x As Object, y As Object) As Integer implements IComparer.Compare
        Dim s1 As String = CStr (x)
        Dim s2 As String = CStr (y)
        
        'negate the return value to get the reverse order
        Return - [String].Compare(s1, s2)
    
    End Function 'Compare
End Class

Remarks

The comparison is performed using word sort rules. For more information about word, string, and ordinal sorts, see System.Globalization.CompareOptions.

Warning

One or both comparands can be null. By definition, any string, including the empty string (""), compares greater than a null reference; and two null references compare equal to each other.

The comparison terminates when an inequality is discovered or both strings have been compared. However, if the two strings compare equal to the end of one string, and the other string has characters remaining, then the string with remaining characters is considered greater. The return value is the result of the last comparison performed.

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, true) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, true) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, true) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, True) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Compare the path name to "file" using an ordinal comparison. The correct code to do this is as follows:

static bool IsFileURI(String^ path)
{
    return (String::Compare(path, 0, "file:", 0, 5, StringComparison::OrdinalIgnoreCase) == 0);
}

static bool IsFileURI(String path)
{
    return (String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) == 0);
}

let isFileURI path =
    String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0

Shared Function IsFileURI(ByVal path As String) As Boolean
    If String.Compare(path, 0, "file:", 0, 5, StringComparison.OrdinalIgnoreCase) = 0 Then
        Return True
    Else
        Return False
    End If
End Function

Notes to Callers

Character sets include ignorable characters. The Compare(String, String) method does not consider such characters when it performs a culture-sensitive comparison. For example, if the following code is run on the .NET Framework 4 or later, a culture-sensitive comparison of "animal" with "ani-mal" (using a soft hyphen, or U+00AD) indicates that the two strings are equivalent.

string s1 = "ani\u00ADmal";
string s2 = "animal";

Console.WriteLine("Comparison of '{0}' and '{1}': {2}",
                s1, s2, String.Compare(s1, s2));

// The example displays the following output:
//       Comparison of 'ani-mal' and 'animal': 0

open System

let s1 = "ani\u00ADmal"
let s2 = "animal"

printfn $"Comparison of '{s1}' and '{s2}': {String.Compare(s1, s2)}"

// The example displays the following output:
//       Comparison of 'ani-mal' and 'animal': 0

Module Example
   Public Sub Main()
      Dim s1 As String = "ani" + ChrW(&h00AD) + "mal"
      Dim s2 As String = "animal"
      
      Console.WriteLine("Comparison of '{0}' and '{1}': {2}", 
                        s1, s2, String.Compare(s1, s2))
  End Sub
End Module
' The example displays the following output:
'       Comparison of 'ani-mal' and 'animal': 0

Applies to

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String.Compare Method

Definition

Overloads

Remarks

Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions)

Parameters

Returns

Exceptions

Examples

Remarks

Notes to Callers

See also

Applies to

Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo)

Parameters

Returns

Exceptions

Examples

Remarks

Notes to Callers

See also

Applies to

Compare(String, Int32, String, Int32, Int32, StringComparison)

Parameters

Returns

Exceptions

Examples

Remarks

Notes to Callers

See also

Applies to

Compare(String, Int32, String, Int32, Int32, Boolean)

Parameters

Returns

Exceptions

Examples

Remarks

Notes to Callers

See also

Applies to

Compare(String, Int32, String, Int32, Int32)

Parameters

Returns

Exceptions

Examples

Remarks

Notes to Callers

See also

Applies to

Compare(String, String, CultureInfo, CompareOptions)

Parameters

Returns

Exceptions

Examples

Remarks

Notes to Callers

See also

Applies to

Compare(String, String, Boolean, CultureInfo)

Parameters

Returns

Examples

Remarks

Notes to Callers

See also

Applies to

Compare(String, String, StringComparison)

Parameters

Returns

Exceptions

Examples

Remarks

Notes to Callers

See also

Applies to

Compare(String, String, Boolean)

Parameters

Returns

Examples