_MEMPUT - QB64Official/qb64 GitHub Wiki

The _MEMPUT statement writes data to a portion of a designated memory block at an OFFSET position.

Syntax

_MEMPUT memoryBlock, bytePosition, sourceVariable [AS type]

Parameter(s)

  • memoryBlock is a _MEM variable type memory block name created by _MEMNEW or the _MEM (function) function.
  • bytePosition is the memoryBlock.OFFSET start position plus any bytes needed to read specific values.
  • The sourceVariable type designates the size and bytePosition it should be written to. It can be a variable, arrays or user defined type.
  • bytePosition can be converted AS a specific variable TYPE before being written to the memoryBlock as bytes.

Description

  • The _MEMPUT statement is similar to the PUT file statement, but bytePosition is required.
  • The memoryBlock.OFFSET returns the starting byte position of the block. Add bytes to move into the block.
  • The variable type held in the memory block can determine the next byte position to write a value.
  • LEN can be used to determine the byte size of numerical or user defined variable Variable Typess regardless of the value held.
  • STRING values should be of a defined length. Variable length strings can actually move around in memory and not be found.

Example(s)

_MEMPUT can be used just like POKE without DEF SEG.


DIM o AS _MEM
o = _MEM(d&)
_MEMPUT o, o.OFFSET + 1, 3 AS _UNSIGNED _BYTE  'POKE
v = _MEMGET(o, o.OFFSET + 1, _UNSIGNED _BYTE) 'PEEK
PRINT v 'prints 3
PRINT d& 'print 768 because the 2nd byte of d& has been set to 3 or 3 * 256

See Also