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Interlocked.Add Method (Int32, Int32)

Adds two 32-bit integers and replaces the first integer with the sum, as an atomic operation.

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

public static int Add (
	ref int location1,
	int value
public static int Add (
	/** @ref */ int location1, 
	int value
Not applicable.



A variable containing the first value to be added. The sum of the two values is stored in location1.


The value to be added to the integer at location1.

Return Value

The new value stored at location1.

Exception typeCondition


The address of location1 is a null pointer.

This method handles an overflow condition by wrapping: if the value at location1 is Int32.MaxValue and value is 1, the result is Int32.MinValue; if value is 2, the result is (Int32.MinValue + 1); and so on. No exception is thrown.

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0