QB64-PE/internal/help/_MEMGET_(function).txt

{{DISPLAYTITLE:_MEMGET (function)}}
The '''_MEMGET''' function returns a value from a specific memory block name at the specified OFFSET using a certain variable type.


{{PageSyntax}}
::: returnvalue = '''_MEMGET(''memory_block'', ''byte_position'', ''variable_type'')'''


{{Parameters}}
* Returns a value of the ''variable type'' designated. The holding variable must match that [[TYPE]]!
* ''memory block'' is a [[_MEM]] variable type memory block name created by [[_MEMNEW]] or the [[_MEM (function)|_MEM]] function.
* mandatory ''byte_position'' is the ''memory_block.[[OFFSET]]'' memory start position plus any bytes to move into the block. 
* ''variable type'' is a variable [[TYPE]] like [[_BYTE]], [[INTEGER]], [[SINGLE]], [[DOUBLE]], etc.


''Usage:''
* The memory block name.[[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 read. 
* [[LEN]](variable) can determine the byte size of numerical or user defined variable [[type]]s irregardless 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.
* '''_MEMGET variable values that are assigned a variable [[type]] other than a memory type do not need to be freed!'''


''Example:'' [[DEF SEG]] and [[VARPTR]] are no longer necessary to do things in memory just like [[POKE]] and [[PEEK]] do.
{{CodeStart}} '' ''
{{Cl|DIM}} o {{Cl|AS}} {{Cl|_MEM}}
o = {{Cl|_MEM (function)|_MEM}}(d&) 'OLD... o% = VARPTR(d&)
{{Cl|_MEMPUT}} o, o.OFFSET + 1, 3 {{Cl|AS}} {{Cl|_UNSIGNED}} {{Cl|_BYTE}} 'a POKE
v = {{Cl|_MEMGET (function)|_MEMGET}}(o, o.OFFSET + 1, {{Cl|_UNSIGNED}} {{Cl|_BYTE}}) 'a PEEK
{{Cl|PRINT}} v     'prints 3
{{Cl|PRINT}} d&    'prints 768 because the 2nd byte of d& has been set to 3 or 3 * 256
{{Cl|_MEMFREE}} o
{{CodeEnd}}
:''Explanation:'' The memory block and OFFSET are given by [[_MEMPUT]] and the _MEMGET function, with the designated type.


''See also:''
* [[_MEM]], [[MEM (function)]]
* [[_MEMGET]], [[_MEMPUT]]
* [[_MEMNEW]], [[_MEMFILL]]
* [[_MEMCOPY]]


{{PageNavigation}}