QB64-PE/internal/help/CLEAR.txt

The ''CLEAR''' statement clears all variable and array element values in a program. It does not affect constant values! 


''Syntax:'' '''CLEAR''' [, ''stacksize&'' , ''stackspace&'']


{{PageDescription}}
* Optional ''stacksize'' parameter was not required as Qbasic managed that. '''All parameters and commas are ignored by QB64!'''
* The ''stackspace'' parameter sets the stack space to be added to the stack. Two commas kept Qbasic compatible with BASICA.
* Normally used to clear all program variable and [[Arrays|array]] values where numerical values become zero and string values become null.
* It does not clear [[CONST|constant]] values.
* Closes all opened files also.
* [[$DYNAMIC]] or [[REDIM]] arrays will need to be [[REDIM|re-dimensioned]] or an [[ERROR Codes|error]] will occur when referenced because it was removed.


''Example:'' Using CLEAR to clear array elements from [[STATIC|static]] arrays or arrays created using [[DIM]].
{{CodeStart}} '' ''
{{Cl|CLS}}
{{Cl|DIM}} array(10)   'create a {{Cl|$STATIC}} array
array(5) = 23

{{Cl|PRINT}} array(5)

{{Cl|CLEAR}}

{{Cl|PRINT}} array(5) '' ''
{{CodeEnd}}
:''Note:'' If you change DIM to REDIM a "Subscript out of range" error will occur because a [[$DYNAMIC]] array is removed by CLEAR.


{{PageSeeAlso}}
* [[ERASE]] {{text|(array names only)}}
* [[REDIM]] {{text|(array sizes only)}}
* [[_PRESERVE]] {{text|(REDIM arrays only)}}
* [[Arrays]], [[&B|_BIT arrays]]


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