String.Equals Method (String, String) (System)

Equals Method (String, String)

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

String..::.Equals Method (String, String)

Updated: November 2007

Determines whether two specified String objects have the same value.

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

Syntax

Visual Basic (Declaration)

Public Shared Function Equals ( _
    a As String, _
    b As String _
) As Boolean

Visual Basic (Usage)

Dim a As String
Dim b As String
Dim returnValue As Boolean

returnValue = String.Equals(a, b)

public static bool Equals(
    string a,
    string b
)

Visual C++

public:
static bool Equals(
    String^ a, 
    String^ b
)

public static boolean Equals(
    String a,
    String b
)

JScript

public static function Equals(
    a : String, 
    b : String
) : boolean

Parameters

a: Type: System..::.String
A String or nullNothingnullptra null reference (Nothing in Visual Basic).

b: Type: System..::.String
A String or nullNothingnullptra 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

This method performs an ordinal (case-sensitive and culture-insensitive) comparison.

Examples

The following code example demonstrates the Equals method.

Visual Basic

' Sample for String.Equals(Object)
'            String.Equals(String)
'            String.Equals(String, String)
Imports System
Imports System.Text

Class Sample
   Public Shared Sub Main()
      Dim sb As New StringBuilder("abcd")
      Dim str1 As [String] = "abcd"
      Dim str2 As [String] = Nothing
      Dim o2 As [Object] = Nothing

      Console.WriteLine()
      Console.WriteLine(" *  The value of String str1 is '{0}'.", str1)
      Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString())

      Console.WriteLine()
      Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.")
      Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb))

      Console.WriteLine()
      Console.WriteLine("1b) String.Equals(Object). Object is a String.")
      str2 = sb.ToString()
      o2 = str2
      Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2)
      Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2))

      Console.WriteLine()
      Console.WriteLine(" 2) String.Equals(String)")
      Console.WriteLine(" *  The value of String str2 is '{0}'.", str2)
      Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2))

      Console.WriteLine()
      Console.WriteLine(" 3) String.Equals(String, String)")
      Console.WriteLine("    Is str1 equal to str2?: {0}", [String].Equals(str1, str2))
   End Sub 'Main
End Class 'Sample
'
'This example produces the following results:
'
' *  The value of String str1 is 'abcd'.
' *  The value of StringBuilder sb is 'abcd'.
'
'1a) String.Equals(Object). Object is a StringBuilder, not a String.
'    Is str1 equal to sb?: False
'
'1b) String.Equals(Object). Object is a String.
' *  The value of Object o2 is 'abcd'.
'    Is str1 equal to o2?: True
'
' 2) String.Equals(String)
' *  The value of String str2 is 'abcd'.
'    Is str1 equal to str2?: True
'
' 3) String.Equals(String, String)
'    Is str1 equal to str2?: True
'

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
using System;
using System.Text;

class Sample {
    public static void Main() {
    StringBuilder sb = new StringBuilder("abcd");
    String      str1 = "abcd";
    String      str2 = null;
    Object    o2   = null;

    Console.WriteLine();
    Console.WriteLine(" *  The value of String str1 is '{0}'.", str1);
    Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString());

    Console.WriteLine();
    Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.");
    Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb));

    Console.WriteLine();
    Console.WriteLine("1b) String.Equals(Object). Object is a String.");
    str2 = sb.ToString();
    o2   = str2;
    Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2);
    Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2));

    Console.WriteLine();
    Console.WriteLine(" 2) String.Equals(String)");
    Console.WriteLine(" *  The value of String str2 is '{0}'.", str2);
    Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2));

    Console.WriteLine();
    Console.WriteLine(" 3) String.Equals(String, String)");
    Console.WriteLine("    Is str1 equal to str2?: {0}", String.Equals(str1, str2));
    }
}
/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*/

Visual C++

// Sample for String::Equals(Object)
//            String::Equals(String)
//            String::Equals(String, String)
using namespace System;
using namespace System::Text;
int main()
{
   StringBuilder^ sb = gcnew StringBuilder( "abcd" );
   String^ str1 = "abcd";
   String^ str2 = nullptr;
   Object^ o2 = nullptr;
   Console::WriteLine();
   Console::WriteLine( " *  The value of String str1 is '{0}'.", str1 );
   Console::WriteLine( " *  The value of StringBuilder sb is '{0}'.", sb );
   Console::WriteLine();
   Console::WriteLine( "1a) String::Equals(Object). Object is a StringBuilder, not a String." );
   Console::WriteLine( "    Is str1 equal to sb?: {0}", str1->Equals( sb ) );
   Console::WriteLine();
   Console::WriteLine( "1b) String::Equals(Object). Object is a String." );
   str2 = sb->ToString();
   o2 = str2;
   Console::WriteLine( " *  The value of Object o2 is '{0}'.", o2 );
   Console::WriteLine( "    Is str1 equal to o2?: {0}", str1->Equals( o2 ) );
   Console::WriteLine();
   Console::WriteLine( " 2) String::Equals(String)" );
   Console::WriteLine( " *  The value of String str2 is '{0}'.", str2 );
   Console::WriteLine( "    Is str1 equal to str2?: {0}", str1->Equals( str2 ) );
   Console::WriteLine();
   Console::WriteLine( " 3) String::Equals(String, String)" );
   Console::WriteLine( "    Is str1 equal to str2?: {0}", String::Equals( str1, str2 ) );
}

/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String::Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String::Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String::Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String::Equals(String, String)
    Is str1 equal to str2?: True
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
import System.*;
import System.Text.*;

class Sample
{
    public static void main(String[] args)
    {
        StringBuilder sb = new StringBuilder("abcd");
        String str1 = "abcd";
        String str2 = null;
        Object o2 = null;

        Console.WriteLine();
        Console.WriteLine(" *  The value of String str1 is '{0}'.", str1);
        Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", 
            sb.ToString());

        Console.WriteLine();
        Console.WriteLine("1a) String.Equals(Object). Object is a " 
            + "StringBuilder, not a String.");
        Console.WriteLine("    Is str1 equal to sb?: {0}", 
            System.Convert.ToString(str1.Equals(sb)));

        Console.WriteLine();
        Console.WriteLine("1b) String.Equals(Object). Object is a String.");
        str2 = sb.ToString();
        o2 = str2;
        Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2);
        Console.WriteLine("    Is str1 equal to o2?: {0}", 
            System.Convert.ToString(str1.Equals(o2)));

        Console.WriteLine();
        Console.WriteLine(" 2) String.Equals(String)");
        Console.WriteLine(" *  The value of String str2 is '{0}'.", str2);
        Console.WriteLine("    Is str1 equal to str2?: {0}", 
            System.Convert.ToString(str1.Equals(str2)));

        Console.WriteLine();
        Console.WriteLine(" 3) String.Equals(String, String)");
        Console.WriteLine("    Is str1 equal to str2?: {0}", 
            System.Convert.ToString(String.Equals(str1, str2)));
    } //main
} //Sample
/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*/

Platforms

Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360

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

Version Information