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String.Equality Operator

Determines whether two specified strings have the same value.

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

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

Parameters

a
Type: System.String

The first string to compare, or null.

b
Type: System.String

The second string to compare, or null.

Return Value

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

The Equality method defines the operation of the equality operator for the String class. The operator, in turn, calls the static Equals(String, String) method, which performs an ordinal (case-sensitive and culture-insensitive) comparison.

NoteNote

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.

The following example demonstrates the equality operator.

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

class EqualityOp 
{
    public static void Main() 
    {
        Console.WriteLine( 
            "This example of the String Equality operator\n" +
            "generates the following output.\n" );

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

    static void CompareAndDisplay( string Comparand )
    {
        String  Lower = "abcd";

        Console.WriteLine( 
            "\"{0}\" == \"{1}\" ?  {2}",
            Lower, Comparand, Lower == Comparand );
    }
}

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

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

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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