Peek
 
Gets the value of an arbitrary type at an address in memory

Syntax

Declare Function Peek ( ByVal address As Any Ptr ) ByRef As UByte
Declare Function Peek ( datatype, ByVal address As Any Ptr ) ByRef As datatype

Usage

Peek( [ datatype, ] address )

Parameters

address
The address in memory to get the value from.
datatype
The type of value to get. If omitted, UByte is assumed.

Description

This procedure returns a reference to the value in memory given by a memory address, and is equivalent to:
*cast(ubyte ptr, address)
or
*cast(datatype ptr, address)
thus this keyword can also be used to assign a value to a memory location, similarly to Poke.

Note: When using Peek, the -exx compiler option does not add code for null-pointer checking (no nullity test on the value of address).

Example

Dim i As Integer, p As Integer Ptr
p = @i

Poke Integer, p, 420
Print Peek(Integer, p)

will produce the output:

420

Differences from QB

  • Peek did not support the datatype parameter in QB, and could only return individual bytes.
  • Peek returns a reference in FB, so can be used to set the memory contents of the address, like with Operator * (Value Of).
  • DEF SEG isn't needed anymore because the address space is 32-bit flat in FreeBASIC.

See also