String.Equality Operator (String, String)

.NET Framework (current version)
 
System_CAPS_noteNote

The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Determines whether two specified strings have the same value.

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

C#
C++
F#
VB
Copy 
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. It enables code such as that shown in the Example section. The operator, in turn, calls the static Equals(String, String) method, which performs an ordinal (case-sensitive and culture-insensitive) comparison.

System_CAPS_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.

C#
C++
Copy 
// 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
*/

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
Return to top
Show: