The [[$DYNAMIC]] [[Metacommand|metacommand]] allows the creation of dynamic (changeable) arrays.


{{PageSyntax}} 
:{[[REM]] | ' } [[$DYNAMIC]]


{{PageDescription}}
* QBasic [[Metacommand|metacommands]] require [[REM]] or [[Apostrophe|apostrophe]] (') before them and are always placed at the start of the main module.
* Dynamic arrays can be resized using [[REDIM]]. The array's type cannot be changed.
* All data in the array will be lost when [[REDIM]]ensioned except when [[_PRESERVE]] is used.
* [[REDIM]] [[_PRESERVE]] can preserve and may move the previous array data when the array boundaries change.
* [[_PRESERVE]] allows the [[UBOUND|upper]] and [[LBOUND|lower]] boundaries of an array to be changed. The number of dimensions cannot change.
* [[$DYNAMIC]] arrays must be [[REDIM]]ensioned if [[ERASE]] or [[CLEAR]] are used as the arrays are removed completely.


{{PageExamples}}
''Example:'' [[REDIM]]ing a $DYNAMIC array using [[_PRESERVE]] to retain previous array values.
{{CodeStart}} '' ''
{{Cl|REM}} {{Cl|$DYNAMIC}}             'create dynamic arrays only
{{Cl|DIM}} array(10)            'create array with 11 elements
{{Cl|FOR...NEXT|FOR}} i = 0 {{Cl|TO}} 10
  array(i) = i: {{Cl|PRINT}} array(i); 'set and display element values
{{Cl|NEXT}}
{{Cl|PRINT}}
{{Cl|REDIM}} {{Cl|_PRESERVE}} array(10 {{Cl|TO}} 20)
{{Cl|FOR...NEXT|FOR}} i = 10 {{Cl|TO}} 20
  {{Cl|PRINT}} array(i);
{{Cl|NEXT}}
{{Cl|END}} '' ''
{{CodeEnd}}
{{OutputStart}}0  1  2  3  4  5  6  7  8  9  10

0  1  2  3  4  5  6  7  8  9  10
{{OutputEnd}}


{{PageSeeAlso}}
* [[$STATIC]], [[$INCLUDE]]
* [[DIM]], [[REDIM]], [[_DEFINE]]
* [[STATIC]]
* [[ERASE]], [[CLEAR]]
* [[Arrays]], [[Metacommand]]


{{PageNavigation}}
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