Makale
11/18/2011

String.Equality Operator

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Determines whether two specified String objects have the same value.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

Syntax

'Declaration
Public Shared Operator = ( _
    a As String, _
    b As String _
) As Boolean

public static bool operator ==(
    string a,
    string b
)

Parameters

a
Type: System.String
The first string to compare, or nulla null reference (Nothing in Visual Basic).

b
Type: System.String
The second string to compare, or nulla null reference (Nothing in Visual Basic).

Return Value

Type: System.Boolean
true if the value of a is the same as the value of b; otherwise, false.

Remarks

The Equality method defines the operation of the equality operator for the String class.

This operator is implemented using the Equals method, which means the comparands are tested for a combination of reference and value equality. This operator performs an ordinal comparison.

Note:
The Visual Basic compiler does not resolve the equality operator as a call to the Equality method. Instead, the equality operator wraps a call to the Operators.CompareString method.

Examples

The following code example demonstrates the equality operator.

// Example for the String Equality operator.
using System;

class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      outputBlock.Text +=
          "This example of the String Equality operator\n" +
          "generates the following output.\n" + "\n";

      CompareAndDisplay(outputBlock, "ijkl");
      CompareAndDisplay(outputBlock, "ABCD");
      CompareAndDisplay(outputBlock, "abcd");
   }

   static void CompareAndDisplay(System.Windows.Controls.TextBlock outputBlock, string Comparand)
   {
      String Lower = "abcd";

      outputBlock.Text += String.Format(
          "\"{0}\" == \"{1}\" ?  {2}",
          Lower, Comparand, Lower == Comparand) + "\n";
   }
}

/*
This example of the String Equality operator 
generates the following output.

"abcd" == "ijkl" ?  False
"abcd" == "ABCD" ?  False
"abcd" == "abcd" ?  True
*/

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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