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Object::ReferenceEquals Method

.NET Framework 3.5

Other Versions

Updated: September 2010

Determines whether the specified Object instances are the same instance.

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

Syntax

C++

JScript

public:
static bool ReferenceEquals(
	Object^ objA, 
	Object^ objB
)

Parameters

objA: Type: System::Object
The first object to compare.

objB: Type: System::Object
The second object to compare.

Return Value

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

Remarks

Unlike the Equals method and the equality operator, the ReferenceEquals method cannot be overridden. Because of this, if you want to test two object references for equality and are unsure about the implementation of the Equals method, you can call the ReferenceEquals method. However, note that if objA and objB are value types, they are boxed before they are passed to the ReferenceEquals method.

Examples

The following code example uses ReferenceEquals to determine if two objects are the same instance.

C++

JScript

using namespace System;
int main()
{
   Object^ o = nullptr;
   Object^ p = nullptr;
   Object^ q = gcnew 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

*/

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, 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, Zune

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