ZeroMemory Function

Declare Sub ZeroMemory Lib "kernel32.dll" Alias "RtlZeroMemory" (Destination As Any, ByVal Length As Long)

Platforms

Windows 95: Supported.
Windows 98: Supported.
Windows NT: Requires Windows NT 3.1 or later.
Windows 2000: Supported.
Windows CE: Not Supported.

Description & Usage

ZeroMemory fills a location in memory with zeros. The function sets each byte starting at the given memory location to zero. The memory location is identified by a pointer to the memory address.

Return Value

ZeroMemory does not return a value.

Visual Basic-Specific Issues

A pointer to any variable can be automatically generated merely by passing that variable as Destination. However, if either a String or a Long holding the desired memory address is passed, the ByVal keyword must preceed it.

Parameters

Destination: A pointer to the location in memory (often the memory address of a variable) to begin filling with zeros.
Length: The number of memory bytes, beginning with the address identified by Destination, to set to zeros.

Example

' Initialize all the elements in an array to the value 0.
Dim bytearray(0 To 9) as Byte  ' array of 10 bytes
Dim c As Integer  ' counter variable

' Fill the memory at bytearray() with zeros.  Note that, to identify the pointer
' to bytearray()'s memory location, it is passed as normal.
ZeroMemory bytearray(0), 10  ' zero out 10 bytes
' Display the results to verify that it worked.
For c = 0 To 9  ' loop through each element
  Debug.Print bytearray(c);  ' each value displayed will be 0
Next c

Related Function

FillMemory