qb64/internal/help/_MEMEXISTS.txt

{{DISPLAYTITLE:_MEMEXISTS}}
The [[_MEMEXISTS]] function returns true (-1) if the memory block variable name specified exists in memory and false (0) if it does not.


{{PageSyntax}}
: {{Parameter|result}} = [[_MEMEXISTS]]({{Parameter|memBlock}})


{{PageDescription}}
* The {{Parameter|memBlock}} variable name must have been created using [[DIM]] memBlock [[AS]] [[_MEM]] type ([[DIM]].
* The function verifies that the memory variable exists in memory before using a passed block, to avoid generating QB64 errors.
* Typically, this function is used by a [[DECLARE LIBRARY|LIBRARY]] [[SUB]] or [[FUNCTION]] which accepts a [[_MEM]] structure as input, to avoid an error.


{{Parameter|See Also:}}
* [[_MEM (function)]]
* [[_MEMELEMENT]], [[_MEMCOPY]]
* [[_MEMIMAGE]], [[_MEMNEW]]
* [[_MEMGET]], [[_MEMPUT]]
* [[_MEMFILL]], [[_MEMFREE]]


{{PageNavigation}}