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Object.ReferenceEquals Method

Determines whether the specified Object instances are the same instance.

[Visual Basic]
Public Shared Function ReferenceEquals( _
   ByVal objA As Object, _
   ByVal objB As Object _
) As Boolean
[C#]
public static bool ReferenceEquals(
 object objA,
 object objB
);
[C++]
public: static bool ReferenceEquals(
 Object* objA,
 Object* objB
);
[JScript]
public static function ReferenceEquals(
   objA : Object,
 objB : Object
) : Boolean;

Parameters

objA
The first Object to compare.
objB
The second Object to compare.

Return Value

true if objA is the same instance as objB or if both are null references; otherwise, false.

Example

[C#, C++, JScript] The following code example uses ReferenceEquals to determine if two objects are the same instance.

[C#] 
using System;

class MyClass {

   static void Main() {
      object o = null;
      object p = null;
      object q = new Object();

      Console.WriteLine(Object.ReferenceEquals(o, p));
      p = q;
      Console.WriteLine(Object.ReferenceEquals(p, q));
      Console.WriteLine(Object.ReferenceEquals(o, p));
   }
}


/*

This code produces the following output.

True
True
False

*/

[C++] 
#using <mscorlib.dll>
using namespace System;

int main() {
   Object* o = 0;
   Object* p = 0;
   Object* q = new Object();

   Console::WriteLine(Object::ReferenceEquals(o, p));
   p = q;
   Console::WriteLine(Object::ReferenceEquals(p, q));
   Console::WriteLine(Object::ReferenceEquals(o, p));
}

/*

This code produces the following output.

True
True
False

*/

[JScript] 
import System

class MyClass {

   static function Main() {
      var o = null;
      var p = null;
      var q = new Object();

      Console.WriteLine(Object.ReferenceEquals(o, p));
      p = q;
      Console.WriteLine(Object.ReferenceEquals(p, q));
      Console.WriteLine(Object.ReferenceEquals(o, p));
   }
}

MyClass.Main();

/*

This code produces the following output.

True
True
False

*/

[Visual Basic] No example is available for Visual Basic. To view a C#, C++, or JScript example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family, Common Language Infrastructure (CLI) Standard

See Also

Object Class | Object Members | System Namespace | Equals

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