String.Equals 方法

定義

命名空間:: System

組件:: mscorlib.dll, System.Runtime.dll

組件:: netstandard.dll, System.Runtime.dll

組件:: System.Runtime.dll

組件:: mscorlib.dll

組件:: netstandard.dll

重要

部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。

判斷兩個 String 物件的值是否相同。

多載

名稱	Description
Equals(Object)	判斷此實例與指定物件（必須同時也是 String 物件）值是否相同。
Equals(String)	判斷此實例與另一個指定 String 物件是否具有相同值。
Equals(String, String)	判斷兩個指定 String 物件的值是否相同。
Equals(String, StringComparison)	判斷此字串與指定 String 物件值是否相同。參數指定比較中使用的文化、案例及排序規則。
Equals(String, String, StringComparison)	判斷兩個指定 String 物件的值是否相同。參數指定比較中使用的文化、案例及排序規則。

Equals(Object)

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

判斷此實例與指定物件（必須同時也是 String 物件）值是否相同。

public:
 override bool Equals(System::Object ^ obj);

public override bool Equals(object obj);

public override bool Equals(object? obj);

override this.Equals : obj -> bool

Public Overrides Function Equals (obj As Object) As Boolean

參數

obj: Object

用字串來比較這個例子。

傳回

Boolean

true 若 obj 是且 String 其值與此實例相同;否則， false。若 obj ， null則方法返回 false。

範例

以下範例示範此 Equals 方法。

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
using System;
using System.Text;

class Sample1
{
    public static void Main()
    {
        StringBuilder sb = new StringBuilder("abcd");
        String str1 = "abcd";
        String str2 = null;
        Object o2 = null;

        Console.WriteLine();
        Console.WriteLine(" *  The value of String str1 is '{0}'.", str1);
        Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString());

        Console.WriteLine();
        Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.");
        Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb));

        Console.WriteLine();
        Console.WriteLine("1b) String.Equals(Object). Object is a String.");
        str2 = sb.ToString();
        o2 = str2;
        Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2);
        Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2));

        Console.WriteLine();
        Console.WriteLine(" 2) String.Equals(String)");
        Console.WriteLine(" *  The value of String str2 is '{0}'.", str2);
        Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2));

        Console.WriteLine();
        Console.WriteLine(" 3) String.Equals(String, String)");
        Console.WriteLine("    Is str1 equal to str2?: {0}", String.Equals(str1, str2));
    }
}
/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
open System
open System.Text

let sb = StringBuilder "abcd"
let str1 = "abcd"
let str2 = string sb
let o2: obj = str2

printfn $"""
*  The value of String str1 is '{str1}'.
*  The value of StringBuilder sb is '{sb}'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
Is str1 equal to sb?: {str1.Equals sb}"

1b) String.Equals(Object). Object is a String.
*  The value of Object o2 is '{o2}'.
Is str1 equal to o2?: {str1.Equals o2}

2) String.Equals(String)
*  The value of String str2 is '{str2}'.
Is str1 equal to str2?: {str1.Equals str2}

3) String.Equals(String, String)
Is str1 equal to str2?: {String.Equals(str1, str2)}"""
(*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*)

' Sample for String.Equals(Object)
'            String.Equals(String)
'            String.Equals(String, String)
Imports System.Text

Class Sample
   Public Shared Sub Main()
      Dim sb As New StringBuilder("abcd")
      Dim str1 As [String] = "abcd"
      Dim str2 As [String] = Nothing
      Dim o2 As [Object] = Nothing
      
      Console.WriteLine()
      Console.WriteLine(" *  The value of String str1 is '{0}'.", str1)
      Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString())
      
      Console.WriteLine()
      Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.")
      Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb))
      
      Console.WriteLine()
      Console.WriteLine("1b) String.Equals(Object). Object is a String.")
      str2 = sb.ToString()
      o2 = str2
      Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2)
      Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2))
      
      Console.WriteLine()
      Console.WriteLine(" 2) String.Equals(String)")
      Console.WriteLine(" *  The value of String str2 is '{0}'.", str2)
      Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2))
      
      Console.WriteLine()
      Console.WriteLine(" 3) String.Equals(String, String)")
      Console.WriteLine("    Is str1 equal to str2?: {0}", [String].Equals(str1, str2))
   End Sub
End Class
'
'This example produces the following results:
'
' *  The value of String str1 is 'abcd'.
' *  The value of StringBuilder sb is 'abcd'.
'
'1a) String.Equals(Object). Object is a StringBuilder, not a String.
'    Is str1 equal to sb?: False
'
'1b) String.Equals(Object). Object is a String.
' *  The value of Object o2 is 'abcd'.
'    Is str1 equal to o2?: True
'
' 2) String.Equals(String)
' *  The value of String str2 is 'abcd'.
'    Is str1 equal to str2?: True
'
' 3) String.Equals(String, String)
'    Is str1 equal to str2?: True
'

備註

此方法進行序數比較（大小寫區分且不影響文化）。

另請參閱

適用於

Equals(String)

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

判斷此實例與另一個指定 String 物件是否具有相同值。

public:
 virtual bool Equals(System::String ^ value);

public:
 bool Equals(System::String ^ value);

public bool Equals(string value);

public bool Equals(string? value);

override this.Equals : string -> bool

Public Function Equals (value As String) As Boolean

參數

value: String

用字串來比較這個例子。

傳回

Boolean

true 若參數值 value 與此實例值相同;否則， false。若 value ， null則方法返回 false。

實作

Equals(T)

範例

以下範例示範此 Equals 方法。它比較了標題大寫的「File」與一個等價詞、其小寫等價詞、大寫等價詞，以及包含拉丁小寫字母無點 I（U+0131）而非拉丁小寫字母 I（U+0069）的詞。由於該 Equals(String) 方法執行序數比較，只有與相同字的比較會返回 true。

using System;

public class Example
{
    public static void Main()
    {
        Console.OutputEncoding = System.Text.Encoding.UTF8;
        string word = "File";
        string[] others = { word.ToLower(), word, word.ToUpper(), "Fıle" };
        foreach (string other in others)
        {
            if (word.Equals(other))
                Console.WriteLine("{0} = {1}", word, other);
            else
                Console.WriteLine("{0} {1} {2}", word, '\u2260', other);
        }
    }
}
// The example displays the following output:
//       File ≠ file
//       File = File
//       File ≠ FILE
//       File ≠ Fıle

open System

Console.OutputEncoding <- Text.Encoding.UTF8
let word = "File"
let others = [| word.ToLower(); word; word.ToUpper(); "Fıle" |]
for other in others do
    if word.Equals other then
        printfn $"{word} = {other}"
    else
        printfn $"{word} \u2260 {other}"
// The example displays the following output:
//       File ≠ file
//       File = File
//       File ≠ FILE
//       File ≠ Fıle

Module Example
   Public Sub Main()
      Console.OutputEncoding = System.Text.Encoding.UTF8
      
      Dim word As String = "File"
      Dim others() As String = { word.ToLower(), word, word.ToUpper(), _
                                 "Fıle" }
      For Each other As String In others
         If word.Equals(other) Then 
            Console.WriteLine("{0} = {1}", word, other)
         Else
            Console.WriteLine("{0} {1} {2}", word, ChrW(&H2260), other)
         End If      
      Next        
   End Sub
End Module
' The example displays the following output:
'       File ≠ file
'       File = File
'       File ≠ FILE
'       File ≠ Fıle

備註

此方法進行序數比較（大小寫區分且不影響文化）。

另請參閱

CompareOrdinal(String, String)

適用於

Equals(String, String)

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

判斷兩個指定 String 物件的值是否相同。

public:
 static bool Equals(System::String ^ a, System::String ^ b);

public static bool Equals(string a, string b);

public static bool Equals(string? a, string? b);

static member Equals : string * string -> bool

Public Shared Function Equals (a As String, b As String) As Boolean

參數

a: String

第一個比較的字串，或 null。

b: String

第二串比較，或 null。

傳回

Boolean

true 若的 a 值與的 b值相同;否則， false。若和皆a為 b，則方法返回 null。true

範例

以下範例示範此 Equals 方法。

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
using System;
using System.Text;

class Sample1
{
    public static void Main()
    {
        StringBuilder sb = new StringBuilder("abcd");
        String str1 = "abcd";
        String str2 = null;
        Object o2 = null;

        Console.WriteLine();
        Console.WriteLine(" *  The value of String str1 is '{0}'.", str1);
        Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString());

        Console.WriteLine();
        Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.");
        Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb));

        Console.WriteLine();
        Console.WriteLine("1b) String.Equals(Object). Object is a String.");
        str2 = sb.ToString();
        o2 = str2;
        Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2);
        Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2));

        Console.WriteLine();
        Console.WriteLine(" 2) String.Equals(String)");
        Console.WriteLine(" *  The value of String str2 is '{0}'.", str2);
        Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2));

        Console.WriteLine();
        Console.WriteLine(" 3) String.Equals(String, String)");
        Console.WriteLine("    Is str1 equal to str2?: {0}", String.Equals(str1, str2));
    }
}
/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
open System
open System.Text

let sb = StringBuilder "abcd"
let str1 = "abcd"
let str2 = string sb
let o2: obj = str2

printfn $"""
*  The value of String str1 is '{str1}'.
*  The value of StringBuilder sb is '{sb}'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
Is str1 equal to sb?: {str1.Equals sb}"

1b) String.Equals(Object). Object is a String.
*  The value of Object o2 is '{o2}'.
Is str1 equal to o2?: {str1.Equals o2}

2) String.Equals(String)
*  The value of String str2 is '{str2}'.
Is str1 equal to str2?: {str1.Equals str2}

3) String.Equals(String, String)
Is str1 equal to str2?: {String.Equals(str1, str2)}"""
(*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*)

' Sample for String.Equals(Object)
'            String.Equals(String)
'            String.Equals(String, String)
Imports System.Text

Class Sample
   Public Shared Sub Main()
      Dim sb As New StringBuilder("abcd")
      Dim str1 As [String] = "abcd"
      Dim str2 As [String] = Nothing
      Dim o2 As [Object] = Nothing
      
      Console.WriteLine()
      Console.WriteLine(" *  The value of String str1 is '{0}'.", str1)
      Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString())
      
      Console.WriteLine()
      Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.")
      Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb))
      
      Console.WriteLine()
      Console.WriteLine("1b) String.Equals(Object). Object is a String.")
      str2 = sb.ToString()
      o2 = str2
      Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2)
      Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2))
      
      Console.WriteLine()
      Console.WriteLine(" 2) String.Equals(String)")
      Console.WriteLine(" *  The value of String str2 is '{0}'.", str2)
      Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2))
      
      Console.WriteLine()
      Console.WriteLine(" 3) String.Equals(String, String)")
      Console.WriteLine("    Is str1 equal to str2?: {0}", [String].Equals(str1, str2))
   End Sub
End Class
'
'This example produces the following results:
'
' *  The value of String str1 is 'abcd'.
' *  The value of StringBuilder sb is 'abcd'.
'
'1a) String.Equals(Object). Object is a StringBuilder, not a String.
'    Is str1 equal to sb?: False
'
'1b) String.Equals(Object). Object is a String.
' *  The value of Object o2 is 'abcd'.
'    Is str1 equal to o2?: True
'
' 2) String.Equals(String)
' *  The value of String str2 is 'abcd'.
'    Is str1 equal to str2?: True
'
' 3) String.Equals(String, String)
'    Is str1 equal to str2?: True
'

備註

此方法進行序數比較（大小寫區分且不影響文化）。

另請參閱

CompareOrdinal(String, String)

適用於

Equals(String, StringComparison)

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

判斷此字串與指定 String 物件值是否相同。參數指定比較中使用的文化、案例及排序規則。

public:
 bool Equals(System::String ^ value, StringComparison comparisonType);

public bool Equals(string value, StringComparison comparisonType);

public bool Equals(string? value, StringComparison comparisonType);

override this.Equals : string * StringComparison -> bool

Public Function Equals (value As String, comparisonType As StringComparison) As Boolean

參數

value: String

用字串來比較這個例子。

comparisonType: StringComparison

其中一個列舉值，用來指定字串的比較方式。

傳回

Boolean

true 如果參數 value 值與此字串相同;否則， false。

例外狀況

ArgumentException

comparisonType 不是一個 StringComparison 數值。

範例

以下範例建立一個字串陣列，包含大寫「I」、「小寫 i」和無點「ı」。接著它會呼叫 Equals(String, StringComparison) 方法來比較，使用每個可能 StringComparison 的列舉值。

using System;

class Sample 
{
   public static void Main() 
   {
      // Define a string array with the following three "I" characters:
      //      U+0069, U+0131, and U+0049.  
      string[] threeIs = { "i", "ı", "I" };
      // Define Type object representing StringComparison type.
      Type scType = typeof(StringComparison);  
      
      // Show the current culture (for culture-sensitive string comparisons).
      Console.WriteLine("The current culture is {0}.\n", 
                        System.Globalization.CultureInfo.CurrentCulture.Name);
        
      // Perform comparisons using each StringComparison member. 
      foreach (string scName in Enum.GetNames(scType))
      {
         StringComparison sc = (StringComparison) Enum.Parse(scType, scName);
         Console.WriteLine("Comparisons using {0}:", sc);
         // Compare each character in character array.
         for (int ctr = 0; ctr <= 1; ctr++)
         {
            string instanceChar = threeIs[ctr];
            for (int innerCtr = ctr + 1; innerCtr <= threeIs.GetUpperBound(0); innerCtr++)
            {
               string otherChar = threeIs[innerCtr];
               Console.WriteLine("{0} (U+{1}) = {2} (U+{3}): {4}", 
                                 instanceChar, Convert.ToInt16(Char.Parse(instanceChar)).ToString("X4"), 
                                 otherChar, Convert.ToInt16(Char.Parse(otherChar)).ToString("X4"), 
                                 instanceChar.Equals(otherChar, sc));
            }
            Console.WriteLine();
         }
      }   
   }
}
// The example displays the following output:
//       The current culture is en-US.
//       
//       Comparisons using CurrentCulture:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using CurrentCultureIgnoreCase:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCulture:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCultureIgnoreCase:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using Ordinal:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using OrdinalIgnoreCase:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       ı (U+0131) = I (U+0049): False

open System
open System.Globalization

// Define a string array with the following three "I" characters:
//      U+0069, U+0131, and U+0049.  
let threeIs = [| "i"; "ı"; "I" |]
// Define Type object representing StringComparison type.
let scType = typeof<StringComparison>  

// Show the current culture (for culture-sensitive string comparisons).
printfn $"The current culture is {CultureInfo.CurrentCulture.Name}.\n"

// Perform comparisons using each StringComparison member. 
for scName in Enum.GetNames scType do
    let sc = Enum.Parse(scType, scName) :?> StringComparison
    printfn $"Comparisons using {sc}:"
    // Compare each character in character array.
    for ctr = 0 to 1 do
        let instanceChar = threeIs[ctr]
        for innerCtr = ctr + 1 to threeIs.GetUpperBound 0 do
            let otherChar = threeIs[innerCtr]
            printfn $"{instanceChar} (U+{Convert.ToInt16(Char.Parse instanceChar):X4}) = {otherChar} (U+{Convert.ToInt16(Char.Parse otherChar):X4}): {instanceChar.Equals(otherChar, sc)}"
        printfn ""
// The example displays the following output:
//       The current culture is en-US.
//       
//       Comparisons using CurrentCulture:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using CurrentCultureIgnoreCase:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCulture:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCultureIgnoreCase:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using Ordinal:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using OrdinalIgnoreCase:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       i (U+0131) = I (U+0049): False

Class Sample
   Public Shared Sub Main() 
      ' Define a string array with the following three "I" characters:
      '      U+0069, U+0131, and U+0049.  
      Dim threeIs() As String = { "i", "ı", "I" }
      ' Define Type object representing StringComparison type.
      Dim scType As Type = GetType(StringComparison)  
      
      ' Show the current culture (for culture-sensitive string comparisons).
      Console.WriteLine("The current culture is {0}." & vbCrLf, _
                        System.Globalization.CultureInfo.CurrentCulture.Name)
        
      ' Perform comparisons using each StringComparison member. 
      For Each scName As String In [Enum].GetNames(scType)
         Dim sc As StringComparison = [Enum].Parse(scType, scName)
         Console.WriteLine("Comparisons using {0}:", sc)
         ' Compare each character in character array.
         For ctr As Integer = 0 To 1
            Dim instanceChar As String = threeIs(ctr)
            For innerCtr As Integer = ctr + 1 To threeIs.GetUpperBound(0)
               Dim otherChar As STring = threeIs(innerCtr)
               Console.WriteLine("{0} (U+{1}) = {2} (U+{3}): {4}", _
                                 instanceChar, Convert.ToInt16(Char.Parse(instanceChar)).ToString("X4"), _
                                 otherChar, Convert.ToInt16(Char.Parse(otherChar)).ToString("X4"), _
                                 instanceChar.Equals(otherChar, sc))
            Next
            Console.WriteLine()
         Next
      Next              
   End Sub
End Class
' The example displays the following output:
'       The current culture is en-US.
'       
'       Comparisons using CurrentCulture:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): False
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using CurrentCultureIgnoreCase:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): True
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using InvariantCulture:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): False
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using InvariantCultureIgnoreCase:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): True
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using Ordinal:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): False
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using OrdinalIgnoreCase:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): True
'       
'       i (U+0131) = I (U+0049): False

備註

該 comparisonType 參數表示比較時應使用當前或不變的文化，還是應尊重或忽略被比較的兩個字串的情況，或是使用字或序數排序規則。

另請參閱

CompareOrdinal(String, String)

適用於

Equals(String, String, StringComparison)

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

來源:: String.Comparison.cs

判斷兩個指定 String 物件的值是否相同。參數指定比較中使用的文化、案例及排序規則。

public:
 static bool Equals(System::String ^ a, System::String ^ b, StringComparison comparisonType);

public static bool Equals(string a, string b, StringComparison comparisonType);

public static bool Equals(string? a, string? b, StringComparison comparisonType);

static member Equals : string * string * StringComparison -> bool

Public Shared Function Equals (a As String, b As String, comparisonType As StringComparison) As Boolean

參數

a: String

第一個比較的字串，或 null。

b: String

第二串比較，或 null。

comparisonType: StringComparison

這是列舉值之一，用來指定比較規則。

傳回

Boolean

true若參數值a等於參數值b;否則，。 false

例外狀況

ArgumentException

comparisonType 不是一個 StringComparison 數值。

範例

以下範例透過使用列舉中的 StringComparison 每個成員來比較三組字串。比較採用英語（美國）、泰語（泰國）及土耳其（土耳其）文化的慣例。請注意，字串「a」和「a-」在「th-TH」文化中被視為等價，但在其他文化中則不然;而在「tr-TR」文化中，忽略格位時「i」和「İ」被視為等價，但在其他文化中則不然。

using System;
using System.Globalization;
using System.Threading;

public class Example3
{
    public static void Main()
    {
        String[] cultureNames = { "en-US", "th-TH", "tr-TR" };
        String[] strings1 = { "a", "i", "case", };
        String[] strings2 = { "a-", "\u0130", "Case" };
        StringComparison[] comparisons = (StringComparison[])Enum.GetValues(typeof(StringComparison));

        foreach (var cultureName in cultureNames)
        {
            Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName);
            Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name);
            for (int ctr = 0; ctr <= strings1.GetUpperBound(0); ctr++)
            {
                foreach (var comparison in comparisons)
                    Console.WriteLine("   {0} = {1} ({2}): {3}", strings1[ctr],
                                      strings2[ctr], comparison,
                                      String.Equals(strings1[ctr], strings2[ctr], comparison));

                Console.WriteLine();
            }
            Console.WriteLine();
        }
    }
}
// The example displays the following output:
//    Current Culture: en-US
//       a = a- (CurrentCulture): False
//       a = a- (CurrentCultureIgnoreCase): False
//       a = a- (InvariantCulture): False
//       a = a- (InvariantCultureIgnoreCase): False
//       a = a- (Ordinal): False
//       a = a- (OrdinalIgnoreCase): False
//
//       i = İ (CurrentCulture): False
//       i = İ (CurrentCultureIgnoreCase): False
//       i = İ (InvariantCulture): False
//       i = İ (InvariantCultureIgnoreCase): False
//       i = İ (Ordinal): False
//       i = İ (OrdinalIgnoreCase): False
//
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//
//
//    Current Culture: th-TH
//       a = a- (CurrentCulture): True
//       a = a- (CurrentCultureIgnoreCase): True
//       a = a- (InvariantCulture): False
//       a = a- (InvariantCultureIgnoreCase): False
//       a = a- (Ordinal): False
//       a = a- (OrdinalIgnoreCase): False
//
//       i = İ (CurrentCulture): False
//       i = İ (CurrentCultureIgnoreCase): False
//       i = İ (InvariantCulture): False
//       i = İ (InvariantCultureIgnoreCase): False
//       i = İ (Ordinal): False
//       i = İ (OrdinalIgnoreCase): False
//
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//
//
//    Current Culture: tr-TR
//       a = a- (CurrentCulture): False
//       a = a- (CurrentCultureIgnoreCase): False
//       a = a- (InvariantCulture): False
//       a = a- (InvariantCultureIgnoreCase): False
//       a = a- (Ordinal): False
//       a = a- (OrdinalIgnoreCase): False
//
//       i = İ (CurrentCulture): False
//       i = İ (CurrentCultureIgnoreCase): True
//       i = İ (InvariantCulture): False
//       i = İ (InvariantCultureIgnoreCase): False
//       i = İ (Ordinal): False
//       i = İ (OrdinalIgnoreCase): False
//
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True

open System
open System.Globalization
open System.Threading

let cultureNames = 
    [| "en-US"; "se-SE" |]
let strings1 = 
    [| "case"; "encyclopædia" 
       "encyclopædia"; "Archæology" |]
let strings2 = 
    [| "Case"; "encyclopaedia" 
       "encyclopedia"; "ARCHÆOLOGY" |]
let comparisons = 
    Enum.GetValues typeof<StringComparison> :?> StringComparison[]

for cultureName in cultureNames do
    Thread.CurrentThread.CurrentCulture <- CultureInfo.CreateSpecificCulture cultureName
    printfn $"Current Culture: {CultureInfo.CurrentCulture.Name}"
    for i = 0 to strings1.GetUpperBound 0 do
        for comparison in comparisons do
            printfn $"   {strings1[i]} = {strings2[i]} ({comparison}): {String.Equals(strings1[i], strings2[i], comparison)}"
        printfn ""         
    printfn ""
// The example displays the following output:
//    Current Culture: en-US
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//    
//       encyclopædia = encyclopaedia (CurrentCulture): True
//       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True
//       encyclopædia = encyclopaedia (InvariantCulture): True
//       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
//       encyclopædia = encyclopaedia (Ordinal): False
//       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
//    
//       encyclopædia = encyclopedia (CurrentCulture): False
//       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
//       encyclopædia = encyclopedia (InvariantCulture): False
//       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
//       encyclopædia = encyclopedia (Ordinal): False
//       encyclopædia = encyclopedia (OrdinalIgnoreCase): False
//    
//       Archæology = ARCHÆOLOGY (CurrentCulture): False
//       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
//       Archæology = ARCHÆOLOGY (InvariantCulture): False
//       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
//       Archæology = ARCHÆOLOGY (Ordinal): False
//       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
//    
//    
//    Current Culture: se-SE
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//    
//       encyclopædia = encyclopaedia (CurrentCulture): False
//       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False
//       encyclopædia = encyclopaedia (InvariantCulture): True
//       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
//       encyclopædia = encyclopaedia (Ordinal): False
//       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
//    
//       encyclopædia = encyclopedia (CurrentCulture): False
//       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
//       encyclopædia = encyclopedia (InvariantCulture): False
//       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
//       encyclopædia = encyclopedia (Ordinal): False
//       encyclopædia = encyclopedia (OrdinalIgnoreCase): False
//    
//       Archæology = ARCHÆOLOGY (CurrentCulture): False
//       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
//       Archæology = ARCHÆOLOGY (InvariantCulture): False
//       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
//       Archæology = ARCHÆOLOGY (Ordinal): False
//       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True

Imports System.Globalization
Imports System.Threading

Module Example
   Public Sub Main()
      Dim cultureNames() As String = { "en-US", "se-SE" }
      Dim strings1() As String = { "case",  "encyclopædia",  
                                   "encyclopædia", "Archæology" }
      Dim strings2() As String = { "Case", "encyclopaedia", 
                                   "encyclopedia" , "ARCHÆOLOGY" }
      Dim comparisons() As StringComparison = CType([Enum].GetValues(GetType(StringComparison)),
                                           StringComparison())
      
      For Each cultureName In cultureNames
         Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName)
         Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name)
         For ctr As Integer = 0 To strings1.GetUpperBound(0)
            For Each comparison In comparisons
               Console.WriteLine("   {0} = {1} ({2}): {3}", strings1(ctr),
                                 strings2(ctr), comparison, 
                                 String.Equals(strings1(ctr), strings2(ctr), comparison))
            Next
            Console.WriteLine()         
         Next
         Console.WriteLine()
      Next
   End Sub
End Module
' The example displays the following output:
'    Current Culture: en-US
'       case = Case (CurrentCulture): False
'       case = Case (CurrentCultureIgnoreCase): True
'       case = Case (InvariantCulture): False
'       case = Case (InvariantCultureIgnoreCase): True
'       case = Case (Ordinal): False
'       case = Case (OrdinalIgnoreCase): True
'    
'       encyclopædia = encyclopaedia (CurrentCulture): True
'       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True
'       encyclopædia = encyclopaedia (InvariantCulture): True
'       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
'       encyclopædia = encyclopaedia (Ordinal): False
'       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
'    
'       encyclopædia = encyclopedia (CurrentCulture): False
'       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
'       encyclopædia = encyclopedia (InvariantCulture): False
'       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
'       encyclopædia = encyclopedia (Ordinal): False
'       encyclopædia = encyclopedia (OrdinalIgnoreCase): False
'    
'       Archæology = ARCHÆOLOGY (CurrentCulture): False
'       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
'       Archæology = ARCHÆOLOGY (InvariantCulture): False
'       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
'       Archæology = ARCHÆOLOGY (Ordinal): False
'       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
'    
'    
'    Current Culture: se-SE
'       case = Case (CurrentCulture): False
'       case = Case (CurrentCultureIgnoreCase): True
'       case = Case (InvariantCulture): False
'       case = Case (InvariantCultureIgnoreCase): True
'       case = Case (Ordinal): False
'       case = Case (OrdinalIgnoreCase): True
'    
'       encyclopædia = encyclopaedia (CurrentCulture): False
'       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False
'       encyclopædia = encyclopaedia (InvariantCulture): True
'       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
'       encyclopædia = encyclopaedia (Ordinal): False
'       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
'    
'       encyclopædia = encyclopedia (CurrentCulture): False
'       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
'       encyclopædia = encyclopedia (InvariantCulture): False
'       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
'       encyclopædia = encyclopedia (Ordinal): False
'       encyclopædia = encyclopedia (OrdinalIgnoreCase): False
'    
'       Archæology = ARCHÆOLOGY (CurrentCulture): False
'       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
'       Archæology = ARCHÆOLOGY (InvariantCulture): False
'       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
'       Archæology = ARCHÆOLOGY (Ordinal): False
'       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True

備註

該 comparisonType 參數表示比較時應使用當前或不變的文化，還是應尊重或忽略被比較的兩個字串的情況，或是使用字或序數排序規則。

另請參閱

CompareOrdinal(String, String)

適用於

意見反應

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