UIntPtr.Subtract Method (UIntPtr, Int32)

.NET Framework (current version)
 

Subtracts an offset from the value of an unsigned pointer.

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

Public Shared Function Subtract (
	pointer As UIntPtr,
	offset As Integer
) As UIntPtr

Parameters

pointer
Type: System.UIntPtr

The unsigned pointer to subtract the offset from.

offset
Type: System.Int32

The offset to subtract.

Return Value

Type: System.UIntPtr

A new unsigned pointer that reflects the subtraction of offset from pointer.

The Subtract method does not throw an exception if the result is too small to represent as a pointer on the specified platform. Instead, the subtraction operation is performed in an unchecked context.

Languages that do not support operator overloading or custom operators can use this method to subtract an offset from the value of an unsigned pointer.

The following example instantiates an IntPtr object that points to the end of a ten-element array, and then calls the Subtract method to iterate the elements in the array in reverse order.

Module Example
   Public Sub Main()
      Dim arr() As Integer = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
      Dim ptr As UIntPtr = CType(arr(arr.GetUpperBound(0)), UIntPtr)
      For ctr As Integer= 0 To arr.GetUpperBound(0)
         Dim newPtr As UIntPtr = UIntPtr.Subtract(ptr, ctr)
         Console.Write("{0}   ", newPtr)
      Next
   End Sub
End Module
' The example displays the following output:
'       10   9   8   7   6   5   4   3   2   1

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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