String.Compare 方法

定義

比較兩個指定的 String 物件,並傳回一個整數,指出它們在排序順序中的相對位置。

多載

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

比較兩個指定的 String 物件的子字串,使用指定的比較選項及特定文化特性資訊影響比較,然後傳回整數,這個整數表示這兩個子字串在排序次序中彼此的關聯性。

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

比較兩個指定之 String 物件的子字串,忽略或區分兩者的大小寫,並使用文化特性資訊來影響比較,然後傳回一個整數,表示兩者在排序順序中的相對位置。

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

使用指定的規則比較兩個指定之 String 物件的子字串,並傳回一個整數,表示兩者在排序順序中的相對位置。

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

比較兩個指定之 String 物件的子字串,忽略或區分兩者的大小寫,並傳回一個整數,表示兩者在排序順序中的相對位置。

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

比較兩個指定的 String 物件子字串,並傳回一個整數,指出它們在排序順序中的相對位置。

Compare(String, String)

比較兩個指定的 String 物件,並傳回一個整數,指出它們在排序順序中的相對位置。

Compare(String, String, Boolean, CultureInfo)

比較兩個指定的 String 物件,忽略或區分兩者的大小寫,並使用特定文化特性資訊來影響比較,然後傳回一個整數,表示兩者在排序順序中的相對位置。

Compare(String, String, StringComparison)

使用指定的規則比較兩個指定的 String 物件,並傳回一個整數,表示兩者在排序順序中的相對位置。

Compare(String, String, Boolean)

比較兩個指定的 String 物件,忽略或區分兩者的大小寫,並傳回一個整數,表示兩者在排序順序中的相對位置。

Compare(String, String, CultureInfo, CompareOptions)

比較兩個指定的 String 物件,使用指定的比較選項及特定文化特性資訊影響比較,然後傳回整數,這個整數表示這兩個字串在排序次序中彼此的關聯性。

備註

Compare 方法的所有多載會傳回 32 位元帶正負號整數,指出兩個比較元之間的語彙關係。

條件
小於零 第一個子字串在排序次序中的第二個子字串之前。
子字串出現在排序次序中的相同位置,或 length 為零。
大於零 第一個子字串會遵循排序次序中的第二個子字串。

警告

可能的話,您應該呼叫包含 StringComparison 參數的方法 Compare 多載。 如需詳細資訊,請參閱使用字串的最佳做法

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

比較兩個指定的 String 物件的子字串,使用指定的比較選項及特定文化特性資訊影響比較,然後傳回整數,這個整數表示這兩個子字串在排序次序中彼此的關聯性。

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

參數

strA
String

要用於比較中的第一個字串。

indexA
Int32

strA 中子字串的開始位置。

strB
String

要用於比較的第二個字串。

indexB
Int32

strB 中子字串的開始位置。

length
Int32

要比較之子字串的字元數上限。

culture
CultureInfo

物件,提供文化特性相關的比較資訊。 如果 culturenull,則會使用目前的文化特性。

options
CompareOptions

執行比較時要使用的選項 (例如忽略大小寫或符號)。

傳回

Int32

整數,這個整數表示兩個子字串之間的語彙關係,如下表所示。

條件
小於零 strA 中的子字串的排序次序在 strB 中的子字串之前。
子字串出現在排序次序中的相同位置,或 length 為零。
大於零 strA 中的子字串的排序次序在 strB 中的子字串之後。

例外狀況

options 不是 CompareOptions 值。

indexA 大於 strA.Length

-或-

indexB 大於 strB.Length

-或-

indexAindexBlength 為負。

-或-

strAstrBnull,且 length 大於零。

範例

下列範例會 Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) 使用 方法來比較兩人的姓氏。 然後,它會依字母順序列出它們。

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

備註

要比較的 strA 子字串從 位置 indexA 開始,以及位於 strB 的位置 indexB 。 第一個子字串的長度是 減 的 strAindexA 長度。 第二個子字串的長度是 減去 indexBstrB 長度。

要比較的字元數是兩個子字串 length 和 的長度較小。 indexAindexBlength 參數必須是非負值。

比較會使用 culture 參數來取得特定文化特性的資訊,例如大小寫規則和個別字元的字母順序。 例如,特定文化特性可以指定將字元的特定組合視為單一字元、以特定方式比較大寫和小寫字元,或是字元的排序次序取決於前面或之後的字元。

警告

方法 Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) 主要是設計來用於排序或字母排序作業。 當方法呼叫的主要用途是判斷兩個子字串是否相等 (即,當方法呼叫的目的是要測試傳回值為零) 時,就不應該使用它。 若要判斷兩個字串是否相等,請呼叫 Equals 方法。

和 的 strAstrB 一或兩者可以是 null 。 根據定義,包括 的任何字串 String.Empty 都會比較大於 Null 參考,而兩個 Null 參考會彼此相等。

參數可以進一步指定 options 比較,該參數是由列舉的 System.Globalization.CompareOptions 一或多個成員所組成。 不過,由於此方法的目的是要進行區分文化特性的字串比較, CompareOptions.Ordinal 因此 和 CompareOptions.OrdinalIgnoreCase 值沒有任何作用。

當發現不等比較或已比較兩個子字串時,比較就會終止。 不過,如果兩個字串相等於一個字串的結尾,而另一個字串有剩餘的字元,則會將其餘字元的字串視為更大。 傳回值是上次執行比較的結果。

給呼叫者的注意事項

字元集包含可忽略的字元。 方法 Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) 在執行語言或區分文化特性的比較時,不會考慮這些字元。 若要辨識比較中可忽略的字元,請提供 OrdinalOrdinalIgnoreCase 的值給 options 參數。

另請參閱

適用於

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

比較兩個指定之 String 物件的子字串,忽略或區分兩者的大小寫,並使用文化特性資訊來影響比較,然後傳回一個整數,表示兩者在排序順序中的相對位置。

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

參數

strA
String

要用於比較中的第一個字串。

indexA
Int32

strA 中子字串的位置。

strB
String

要用於比較的第二個字串。

indexB
Int32

strB 中子字串的位置。

length
Int32

要比較之子字串的字元數上限。

ignoreCase
Boolean

true 表示在比較時忽略大小寫,否則為 false

culture
CultureInfo

物件,提供文化特性相關的比較資訊。 如果 culturenull,則會使用目前的文化特性。

傳回

Int32

整數,表示兩個比較元 (Comparand) 之間的語彙關係。

條件
小於零 strA 中的子字串的排序次序在 strB 中的子字串之前。
子字串出現在排序次序中的相同位置,或 length 為零。
大於零 strA 中的子字串的排序次序在 strB 中的子字串之後。

例外狀況

indexA 大於 strA.Length

-或-

indexB 大於 strB.Length

-或-

indexAindexBlength 為負。

-或-

strAstrBnull,且 length 大於零。

範例

下列範例會比較兩個使用不同文化特性的子字串,並忽略子字串的大小寫。 文化特性的選擇會影響字母 「I」 的比較方式。

// 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'.
'

備註

要比較的子字串位於 strAindexA , 和 中的 strBindexB 。 和 indexB 都是 indexA 以零起始的;也就是說,和 strB 中的 strA 第一個字元位於零位置,而不是第一個位置。 第一個子字串的長度等於 減一 indexA 的長度 strA 。 第二個子字串的長度等於 減去 indexB 1 的長度 strB

要比較的字元數是兩個子字串 length 和 的長度較小。 indexAindexBlength 參數必須是非負值。

比較會使用 culture 參數來取得特定文化特性的資訊,例如大小寫規則和個別字元的字母順序。 例如,文化特性可以指定將字元的特定組合視為單一字元,或以特定方式比較大寫和小寫字元,或是字元的排序次序取決於前面或後面的字元。

比較是使用字組排序規則來執行。 如需單字、字串和序數排序的詳細資訊,請參閱 System.Globalization.CompareOptions

一或兩個比較子可以是 null 。 根據定義,任何字串,包括空字串 (「」) ,會比較大於 null 參考;和兩個 Null 參考會彼此相等。

當發現不等比較或已比較兩個子字串時,比較就會終止。 不過,如果兩個字串相等於一個字串的結尾,而另一個字串有剩餘的字元,則會將剩餘字元的字串視為更大。 傳回值是上次執行比較的結果。

當比較受到特定文化特性大小寫規則的影響時,可能會發生非預期的結果。 例如,在土耳其文中,下列範例會產生錯誤的結果,因為土耳其文中的檔案系統不會針對 「file」 中的字母 「i」 使用語言大小寫規則。

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

使用序數比較,將路徑名稱與 「file」 進行比較。 執行這項操作的正確程式碼如下所示:

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

給呼叫者的注意事項

字元集包含可忽略的字元。 方法 Compare(String, Int32, String, Int32, Int32, Boolean, CultureInfo) 在執行語言或區分文化特性的比較時,不會考慮這些字元。 若要辨識比較中可忽略的字元,請呼叫 Compare(String, Int32, String, Int32, Int32, CultureInfo, CompareOptions) 方法,並為 參數提供 或 OrdinalIgnoreCaseoptions 的值 Ordinal

另請參閱

適用於

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

使用指定的規則比較兩個指定之 String 物件的子字串,並傳回一個整數,表示兩者在排序順序中的相對位置。

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

參數

strA
String

要用於比較中的第一個字串。

indexA
Int32

strA 中子字串的位置。

strB
String

要用於比較的第二個字串。

indexB
Int32

strB 中子字串的位置。

length
Int32

要比較之子字串的字元數上限。

comparisonType
StringComparison

其中一個列舉值,指定要用於比較的規則。

傳回

Int32

32 位元帶正負號的整數,表示兩個比較元之間的語彙關係。

條件
小於零 strA 中的子字串的排序次序在 strB 中的子字串之前。
相同排序次序中相同位置出現的子字串,或 length 參數為零。
大於零 strA 中的子字串的排序次序在 strB 中的子字串之後。

例外狀況

indexA 大於 strA.Length

-或-

indexB 大於 strB.Length

-或-

indexAindexBlength 為負。

-或-

indexAindexBnull,且 length 大於零。

comparisonType 不是 StringComparison 值。

範例

下列範例會比較兩個子字串。

// 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'.
'

備註

要比較的子字串從 strA at indexA 和 中的 strBindexB 開始。 和 indexB 都是 indexA 以零起始的;也就是說,和 strB 中的 strA 第一個字元位於零位置,而不是第一個位置。 第一個子字串的長度等於 減一 indexA 的長度 strA 。 第二個子字串的長度等於 減去 indexB 1 的長度 strB

要比較的字元數是兩個子字串 length 和 的長度較小。 indexAindexBlength 參數必須是非負值。

參數 comparisonType 會指出比較應該使用目前或不因文化特性而異的文化特性、接受或忽略比較子的大小寫,或使用區分文化特性的字組 () 或序數 (不區分文化特性) 排序規則。

一或兩個比較子可以是 null 。 根據定義,任何字串,包括空字串 (「」) ,會比較大於 null 參考;和兩個 Null 參考會彼此相等。

當發現不等比較或已比較兩個子字串時,比較就會終止。 不過,如果兩個字串與一個字串的結尾相等,而另一個字串有剩餘的字元,則會將剩餘字元的字串視為更大。 傳回值是上次執行比較的結果。

當比較受到特定文化特性大小寫規則的影響時,可能會發生非預期的結果。 例如,在土耳其文中,下列範例會產生錯誤的結果,因為土耳其文中的檔案系統不會針對 「file」 中的字母 「i」 使用語言大小寫規則。

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

使用序數比較,將路徑名稱與 「file」 進行比較。 執行這項操作的正確程式碼如下所示:

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

給呼叫者的注意事項

字元集包含可忽略的字元。 方法 Compare(String, Int32, String, Int32, Int32, StringComparison) 在執行語言或區分文化特性的比較時,不會考慮這些字元。 若要辨識比較中可忽略的字元,請提供 OrdinalOrdinalIgnoreCase 的值給 comparisonType 參數。

另請參閱

適用於

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

比較兩個指定之 String 物件的子字串,忽略或區分兩者的大小寫,並傳回一個整數,表示兩者在排序順序中的相對位置。

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

參數

strA
String

要用於比較中的第一個字串。

indexA
Int32

strA 中子字串的位置。

strB
String

要用於比較的第二個字串。

indexB
Int32

strB 中子字串的位置。

length
Int32

要比較之子字串的字元數上限。

ignoreCase
Boolean

true 表示在比較時忽略大小寫,否則為 false

傳回

Int32

32 位元帶正負號的整數,表示兩個比較元之間的語彙關係。

條件
小於零 strA 中的子字串的排序次序在 strB 中的子字串之前。
子字串出現在排序次序中的相同位置,或 length 為零。
大於零 strA 中的子字串的排序次序在 strB 中的子字串之後。

例外狀況

indexA 大於 strA.Length

-或-

indexB 大於 strB.Length

-或-

indexAindexBlength 為負。

-或-

indexAindexBnull,且 length 大於零。

範例

下列範例會執行兩個只有大小寫不同之子字串的兩個比較。 第一個比較會忽略案例,而第二個比較會考慮案例。

// 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'.
'

備註

要比較的子字串位於 strAindexA , 和 中的 strBindexB 。 和 indexB 都是 indexA 以零起始的;也就是說,和 strB 中的 strA 第一個字元位於零位置。 第一個子字串的長度等於 減一 indexA 的長度 strA 。 第二個子字串的長度等於 減去 indexB 1 的長度 strB

要比較的字元數是兩個子字串 length 和 的長度較小。 indexAindexBlength 參數必須是非負值。

比較會使用目前的文化特性來取得特定文化特性的資訊,例如大小寫規則和個別字元的字母順序。 例如,文化特性可以指定將字元的特定組合視為單一字元,或以特定方式比較大寫和小寫字元,或是字元的排序次序取決於前面或後面的字元。

比較是使用字組排序規則來執行。 如需單字、字串和序數排序的詳細資訊,請參閱 System.Globalization.CompareOptions

警告

比較字串時,您應該呼叫 Compare(String, Int32, String, Int32, Int32, StringComparison) 方法,這需要您明確指定方法所使用的字串比較類型。 如需詳細資訊,請參閱使用字串的最佳做法

一或兩個比較子可以是 null 。 根據定義,任何字串,包括空字串 (「」) ,會比較大於 null 參考;和兩個 Null 參考會彼此相等。

當發現不等比較或已比較兩個子字串時,比較就會終止。 不過,如果兩個字串相等於一個字串的結尾,而另一個字串有剩餘的字元,則會將剩餘字元的字串視為更大。 傳回值是上次執行的比較結果。

當比較受到文化特性特定大小寫規則影響時,可能會發生非預期的結果。 例如,在土耳其文中,下列範例會產生錯誤的結果,因為土耳其文中的檔案系統不會針對 「file」 中的字母 「i」 使用語言大小寫規則。

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

路徑名稱必須以不可變的方式進行比較。 執行此動作的正確程式碼如下所示。

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

給呼叫者的注意事項

字元集包含可忽略的字元。 方法 Compare(String, Int32, String, Int32, Int32, Boolean) 在執行語言或區分文化特性的比較時,不會考慮這些字元。 若要辨識比較中可忽略的字元,請呼叫 Compare(String, Int32, String, Int32, Int32, StringComparison) 方法,並為 參數提供 或 OrdinalIgnoreCasecomparisonType 的值 Ordinal

另請參閱

適用於

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

比較兩個指定的 String 物件子字串,並傳回一個整數,指出它們在排序順序中的相對位置。

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

參數

strA
String

要用於比較中的第一個字串。

indexA
Int32

strA 中子字串的位置。

strB
String

要用於比較的第二個字串。

indexB
Int32

strB 中子字串的位置。

length
Int32

要比較之子字串的字元數上限。

傳回

Int32

32 位元帶正負號整數,指出兩比較元的語彙關係。

條件
小於零 strA 中的子字串的排序次序在 strB 中的子字串之前。
子字串出現在排序次序中的相同位置,或 length 為零。
大於零 strA 中的子字串的排序次序在 strB 中的子字串之後。

例外狀況

indexA 大於 strA.Length

-或-

indexB 大於 strB.Length

-或-

indexAindexBlength 為負。

-或-

indexAindexBnull,且 length 大於零。

範例

下列範例會比較兩個子字串。

// 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'.
'

備註

要比較的子字串,從 和 indexA 中的 strAstrBindexB 開始。 indexAindexB 都是以零起始的;也就是說,和 strB 中的 strA 第一個字元位於位置零。 第一個子字串的長度等於減去 indexA 加一的長度 strA 。 第二個子字串的長度等於 strB 減號加上 indexB 一。

要比較的字元數目是兩個子字串 length 和 的長度越少。 indexAindexBlength 參數必須是非負值。

比較會使用目前的文化特性來取得特定文化特性的資訊,例如大小寫規則和個別字元的字母順序。 例如,文化特性可以指定將特定字元組合視為單一字元,或以特定方式比較大寫和小寫字元,或是字元的排序次序取決於前面或之後的字元。

比較是使用字組排序規則來執行。 如需字組、字串和序數排序的詳細資訊,請參閱 System.Globalization.CompareOptions

警告

比較字串時,您應該呼叫 Compare(String, Int32, String, Int32, Int32, StringComparison) 方法,這需要您明確指定方法所使用的字串比較類型。 如需詳細資訊,請參閱使用字串的最佳做法

一或兩個比較子可以是 null 。 根據定義,任何字串,包括空字串 (「」) ,會比較大於 null 參考;和兩個 Null 參考彼此相等。

比較會在探索到不等或兩個子字串進行比較時終止。 不過,如果兩個字串相等於一個字串的結尾,而另一個字串有剩餘的字元,則會將具有剩餘字元的字串視為更大。 傳回值是上次執行的比較結果。

當比較受到文化特性特定大小寫規則影響時,可能會發生非預期的結果。 例如,在土耳其文中,下列範例會產生錯誤的結果,因為土耳其文中的檔案系統不會針對 「file」 中的字母 「i」 使用語言大小寫規則。

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

使用序數比較,將路徑名稱與 「file」 進行比較。 執行此動作的正確程式碼如下所示:

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

給呼叫者的注意事項

字元集包含可忽略的字元。 方法 Compare(String, Int32, String, Int32, Int32) 在執行語言或區分文化特性的比較時,不會考慮這些字元。 若要辨識比較中可忽略的字元,請呼叫 Compare(String, Int32, String, Int32, Int32, StringComparison) 方法,並為 參數提供 或 OrdinalIgnoreCasecomparisonType 的值 Ordinal

另請參閱

適用於

Compare(String, String)

比較兩個指定的 String 物件,並傳回一個整數,指出它們在排序順序中的相對位置。

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

參數

strA
String

要比較的第一個字串。

strB
String

要比較的第二個字串。

傳回

Int32

32 位元帶正負號的整數,表示兩個比較元之間的語彙關係。

條件
小於零在排序次序中,strA 會排在 strB 之前。
strA 出現在排序次序中的位置和 strB 相同。
大於零在排序次序中,strA 會排在 strB 之後。

範例

下列範例會 Compare(String, String) 呼叫 方法來比較三組字串。

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

在下列範例中,類別 ReverseStringComparer 示範如何使用 方法評估兩個 Compare 字串。

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

備註

比較會使用目前的文化特性來取得特定文化特性的資訊,例如大小寫規則和個別字元的字母順序。 例如,文化特性可以指定將特定字元組合視為單一字元,或以特定方式比較大寫和小寫字元,或是字元的排序次序取決於前面或之後的字元。

比較是使用字組排序規則來執行。 如需字組、字串和序數排序的詳細資訊,請參閱 System.Globalization.CompareOptions

警告

比較字串時,您應該呼叫 Compare(String, String, StringComparison) 方法,這需要您明確指定方法所使用的字串比較類型。 如需詳細資訊,請參閱使用字串的最佳做法

一或兩個比較子可以是 null 。 根據定義,任何字串,包括空字串 (「」) ,會比較大於 null 參考;和兩個 Null 參考彼此相等。

比較會在探索到不等或兩個字串都已比較時終止。 不過,如果兩個字串相等於一個字串的結尾,而另一個字串有剩餘的字元,則會將具有剩餘字元的字串視為更大。 傳回值是上次執行的比較結果。

當比較受到文化特性特定大小寫規則影響時,可能會發生非預期的結果。 例如,在土耳其文中,下列範例會產生錯誤的結果,因為土耳其文中的檔案系統不會針對 「file」 中的字母 「i」 使用語言大小寫規則。

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

使用序數比較,將路徑名稱與 「file」 進行比較。 執行此動作的正確程式碼如下所示:

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

給呼叫者的注意事項

字元集包含可忽略的字元。 方法 Compare(String, String) 在執行區分文化特性的比較時,不會考慮這類字元。 例如,如果下列程式碼是在.NET Framework 4 或更新版本上執行,則使用軟連字號或 U+00AD) 表示這兩個字串相等的「動物」 與 「ani-mal」 的文化特性比較 (。

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

若要辨識字串比較中的可忽略字元,請呼叫 Compare(String, String, StringComparison) 方法,並為 參數提供 或 OrdinalIgnoreCasecomparisonType 的值 Ordinal

另請參閱

適用於

Compare(String, String, Boolean, CultureInfo)

比較兩個指定的 String 物件,忽略或區分兩者的大小寫,並使用特定文化特性資訊來影響比較,然後傳回一個整數,表示兩者在排序順序中的相對位置。

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

參數

strA
String

要比較的第一個字串。

strB
String

要比較的第二個字串。

ignoreCase
Boolean

true 表示在比較時忽略大小寫,否則為 false

culture
CultureInfo

物件,提供文化特性相關的比較資訊。 如果 culturenull,則會使用目前的文化特性。

傳回

Int32

32 位元帶正負號的整數,表示兩個比較元之間的語彙關係。

條件
小於零在排序次序中,strA 會排在 strB 之前。
strA 出現在排序次序中的位置和 strB 相同。
大於零在排序次序中,strA 會排在 strB 之後。

範例

下列範例示範文化特性如何影響比較。 在捷克文 - 捷克文化特性中,「ch」 是大於 「d」 的單一字元。 不過,在英文 - 美國文化特性中,「ch」 包含兩個字元,而 「c」 小於 「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 = null;

    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
'

備註

比較會使用 culture 參數來取得特定文化特性的資訊,例如大小寫規則和個別字元的字母順序。 例如,文化特性可以指定將字元的特定組合視為單一字元,或以特定方式比較大寫和小寫字元,或是字元的排序次序取決於前面或後面的字元。

比較是使用字組排序規則來執行。 如需單字、字串和序數排序的詳細資訊,請參閱 System.Globalization.CompareOptions

一或兩個比較子可以是 null 。 根據定義,任何字串,包括空字串 (「」) ,會比較大於 null 參考;和兩個 Null 參考會彼此相等。

當發現不相等或已比較這兩個字串時,比較就會終止。 不過,如果兩個字串相等於一個字串的結尾,而另一個字串有剩餘的字元,則會將剩餘字元的字串視為更大。 傳回值是上次執行比較的結果。

當比較受到特定文化特性大小寫規則的影響時,可能會發生非預期的結果。 例如,在土耳其文中,下列範例會產生錯誤的結果,因為土耳其文中的檔案系統不會針對 「file」 中的字母 「i」 使用語言大小寫規則。

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

使用序數比較,將路徑名稱與 「file」 進行比較。 執行這項操作的正確程式碼如下所示:

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

給呼叫者的注意事項

字元集包含可忽略的字元。 方法 Compare(String, String, Boolean, CultureInfo) 在執行區分文化特性的比較時,不會考慮這類字元。 例如,如果下列程式碼是在.NET Framework 4 或更新版本上執行,則使用軟連字號與 「Ani-mal」 (的 「動物」不區分大小寫的比較,或使用不變異文化特性的 U+00AD) 表示這兩個字串相等。

  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

若要辨識字串比較中的可忽略字元,請呼叫 Compare(String, String, CultureInfo, CompareOptions) 方法,並為 參數提供 或 OrdinalIgnoreCaseoptions 的值 Ordinal

另請參閱

適用於

Compare(String, String, StringComparison)

使用指定的規則比較兩個指定的 String 物件,並傳回一個整數,表示兩者在排序順序中的相對位置。

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

參數

strA
String

要比較的第一個字串。

strB
String

要比較的第二個字串。

comparisonType
StringComparison

其中一個列舉值,指定要用於比較的規則。

傳回

Int32

32 位元帶正負號的整數,表示兩個比較元之間的語彙關係。

條件
小於零在排序次序中,strA 會排在 strB 之前。
strA 在排序次序中的位置和 strB 相同。
大於零在排序次序中,strA 會排在 strB 之後。

例外狀況

comparisonType 不是 StringComparison 值。

範例

下列範例會比較字母 「I」 的三個版本。 結果會受到文化特性選擇的影響、是否忽略大小寫,以及是否執行序數比較。

// 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)
'

備註

參數 comparisonType 會指出比較應該使用目前或不因文化特性而異的文化特性、接受或忽略比較子的大小寫,或使用區分文化特性的字組 () 或序數 (不區分文化特性) 排序規則。

一或兩個比較子可以是 null 。 根據定義,任何字串,包括空字串 (「」) ,會比較大於 null 參考;和兩個 Null 參考會彼此相等。

當發現不相等或已比較這兩個字串時,比較就會終止。 不過,如果兩個字串與一個字串的結尾相等,而另一個字串有剩餘的字元,則會將剩餘字元的字串視為更大。 傳回值是上次執行比較的結果。

當比較受到特定文化特性大小寫規則的影響時,可能會發生非預期的結果。 例如,在土耳其文中,下列範例會產生錯誤的結果,因為土耳其文中的檔案系統不會針對 「file」 中的字母 「i」 使用語言大小寫規則。

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

使用序數比較,將路徑名稱與 「file」 進行比較。 執行這項操作的正確程式碼如下所示:

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

給呼叫者的注意事項

字元集包含可忽略的字元。 方法 Compare(String, String, StringComparison) 在執行區分文化特性的比較時,不會考慮這類字元。 若要辨識比較中可忽略的字元,請提供 OrdinalOrdinalIgnoreCase 的值給 comparisonType 參數。

另請參閱

適用於

Compare(String, String, Boolean)

比較兩個指定的 String 物件,忽略或區分兩者的大小寫,並傳回一個整數,表示兩者在排序順序中的相對位置。

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

參數

strA
String

要比較的第一個字串。

strB
String

要比較的第二個字串。

ignoreCase
Boolean

true 表示在比較時忽略大小寫,否則為 false

傳回

Int32

32 位元帶正負號的整數,表示兩個比較元之間的語彙關係。

條件
小於零在排序次序中,strA 會排在 strB 之前。
strA 出現在排序次序中的位置和 strB 相同。
大於零在排序次序中,strA 會排在 strB 之後。

範例

下列範例示範 Compare(String, String, Boolean) 方法相當於在比較字串時使用 ToUpperToLower

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

備註

比較會使用目前的文化特性來取得特定文化特性的資訊,例如大小寫規則和個別字元的字母順序。 例如,文化特性可以指定將字元的特定組合視為單一字元,或以特定方式比較大寫和小寫字元,或是字元的排序次序取決於前面或後面的字元。

比較是使用字組排序規則來執行。 如需單字、字串和序數排序的詳細資訊,請參閱 System.Globalization.CompareOptions

警告

比較字串時,您應該呼叫 Compare(String, String, StringComparison) 方法,這需要您明確指定方法所使用的字串比較類型。 如需詳細資訊,請參閱使用字串的最佳做法

一或兩個比較子可以是 null 。 根據定義,任何字串,包括空字串 (「」) ,會比較大於 null 參考;和兩個 Null 參考會彼此相等。

當發現不相等或已比較這兩個字串時,比較就會終止。 不過,如果兩個字串相等於一個字串的結尾,而另一個字串有剩餘的字元,則會將剩餘字元的字串視為更大。 傳回值是上次執行比較的結果。

當比較受到特定文化特性大小寫規則的影響時,可能會發生非預期的結果。 例如,在土耳其文中,下列範例會產生錯誤的結果,因為土耳其文中的檔案系統不會針對 「file」 中的字母 「i」 使用語言大小寫規則。

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

使用序數比較,將路徑名稱與 「file」 進行比較。 執行這項操作的正確程式碼如下所示:

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

給呼叫者的注意事項

字元集包含可忽略的字元。 方法 Compare(String, String, Boolean) 在執行區分文化特性的比較時,不會考慮這類字元。 例如,如果下列程式碼是在 .NET Framework 4 或更新版本上執行,則區分文化特性、不區分大小寫的 「animal」 與 「Ani-mal」 (使用軟連字號或 U+00AD) 表示這兩個字串相等。

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

若要辨識字串比較中的可忽略字元,請呼叫 Compare(String, String, StringComparison) 方法,並為 參數提供 或 OrdinalIgnoreCasecomparisonType 的值 Ordinal

另請參閱

適用於

Compare(String, String, CultureInfo, CompareOptions)

比較兩個指定的 String 物件,使用指定的比較選項及特定文化特性資訊影響比較,然後傳回整數,這個整數表示這兩個字串在排序次序中彼此的關聯性。

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

參數

strA
String

要比較的第一個字串。

strB
String

要比較的第二個字串。

culture
CultureInfo

提供特定文化特性之比較資訊的文化特性。 如果 culturenull,則會使用目前的文化特性。

options
CompareOptions

執行比較時要使用的選項 (例如忽略大小寫或符號)。

傳回

Int32

32 位元帶正負號的整數,這個整數表示 strAstrB 之間的語彙關係,如下表所示。

條件
小於零在排序次序中,strA 會排在 strB 之前。
strA 出現在排序次序中的位置和 strB 相同。
大於零在排序次序中,strA 會排在 strB 之後。

例外狀況

options 不是 CompareOptions 值。

範例

下列範例會以三種不同的方式比較兩個字串:使用 en-US 文化特性的語言比較;使用 en-US 文化特性的語言區分大小寫比較;使用序數比較。 它說明三種比較方法如何產生三個不同的結果。

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'.

備註

比較會使用 culture 參數來取得特定文化特性的資訊,例如大小寫規則和個別字元的字母順序。 例如,特定文化特性可以指定將字元的特定組合視為單一字元、以特定方式比較大寫和小寫字元,或是字元的排序次序取決於前面或之後的字元。

警告

方法 Compare(String, String, CultureInfo, CompareOptions) 主要是設計來用於排序或字母排序作業。 當方法呼叫的主要用途是判斷兩個字串是否相等 (也就是說,當方法呼叫的目的是要測試傳回值為零) 時,就不應該使用它。 若要判斷兩個字串是否相等,請呼叫 Equals 方法。

參數可以進一步指定 options 比較,該參數是由列舉的 CompareOptions 一或多個成員所組成。 不過,由於此方法的目的是要進行區分文化特性的字串比較, CompareOptions.Ordinal 因此 和 CompareOptions.OrdinalIgnoreCase 值沒有任何作用。

或兩個比較子可以是 null 。 根據定義,包括 的任何字串 String.Empty 都會比較大於 Null 參考,而兩個 Null 參考會彼此相等。

當發現不相等或已比較這兩個字串時,比較就會終止。 不過,如果兩個字串相等於一個字串的結尾,而另一個字串有剩餘的字元,則會將其餘字元的字串視為更大。

給呼叫者的注意事項

字元集包含可忽略的字元,這些字元在執行語言或區分文化特性的比較時不列入考慮。 方法 Compare(String, String, CultureInfo, CompareOptions) 在執行區分文化特性的比較時,不會考慮這類字元。 若要辨識比較中可忽略的字元,請提供 OrdinalOrdinalIgnoreCase 的值給 options 參數。

另請參閱

適用於