Inequality Operator
Collapse the table of content
Expand the table of content

String.Inequality Operator (String, String)


Determines whether two specified strings have different values.

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 different from the value of b; otherwise, false.

The Inequality method defines the operation of the inequality 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.


   The Visual Basic compiler does not resolve the inequality operator as a call to the Inequality method. Instead, the inequality operator wraps a call to the Operators.CompareString method.

The following example demonstrates the inequality operator.

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

class InequalityOp 
    public static void Main() 
            "This example of the String Inequality 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 Inequality operator
generates the following output.

"abcd" != "ijkl" ?  True
"abcd" != "ABCD" ?  True
"abcd" != "abcd" ?  False

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
Return to top
© 2015 Microsoft