Equality Operator
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String.Equality Operator (String, String)


Determines whether two specified strings have the same value.

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

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


Type: System.String

The first string to compare, or null.

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.


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() 
            "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";

            "\"{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

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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