Difference between revisions of "$DYNAMIC"

From QB64 Wiki
Jump to navigation Jump to search
imported>Clippy
m
imported>Clippy
m
Line 7: Line 7:
  
  
* Metacommands require a [[REM]] or apostrophy ( ' ) before them.
+
* All [[Metacommand]]s require a REM or apostrophy (') before them and are normally placed at the start of the main module.
* Metacommands should be placed at the program start in the main module.
 
 
* Dynamic arrays can be resized using [[REDIM]]. The array's type cannot be changed.
 
* Dynamic arrays can be resized using [[REDIM]]. The array's type cannot be changed.
* All data in the array will be lost when redimensioned in QBasic.
+
* All data in the array will be lost when [[REDIM]]ensioned except when [[_PRESERVE]] is used in QB64 only.
* In '''QB64''', REDIM [[_PRESERVE]] can preserve and move the previous array data when the array boundaries change.
+
* [[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.
+
* [[_PRESERVE]] allows the [[UBOUND|upper]] and [[LBOUND|lower]] boundaries of an array to be changed. The number of dimensions cannot change!
 
* Dynamic arrays can also be resized by the program user's input if desired.
 
* Dynamic arrays can also be resized by the program user's input if desired.
* [[$DYNAMIC|Dynamic]] arrays MUST be [[REDIM]]ensioned if [[ERASE]] or [[CLEAR]] are used to clear the array values.  
+
* $DYNAMIC arrays MUST be [[REDIM]]ensioned if [[ERASE]] or [[CLEAR]] are used as the arrays are removed completely.
  
  

Revision as of 07:12, 12 September 2011

The $DYNAMIC Metacommand allows the creation of dynamic(changeable) array sizes.


Syntax

REM $DYNAMIC


  • All Metacommands require a REM or apostrophy (') before them and are normally 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 REDIMensioned except when _PRESERVE is used in QB64 only.
  • REDIM _PRESERVE can preserve and may move the previous array data when the array boundaries change.
  • _PRESERVE allows the upper and lower boundaries of an array to be changed. The number of dimensions cannot change!
  • Dynamic arrays can also be resized by the program user's input if desired.
  • $DYNAMIC arrays MUST be REDIMensioned if ERASE or CLEAR are used as the arrays are removed completely.


Example: Re-dimensioning a $DYNAMIC array using _PRESERVE.

REM $DYNAMIC 'create dynamic arrays only DIM array(10) 'create array with 11 elements FOR i = 0 TO 10 array(i) = i: PRINT array(i); 'set and display element values NEXT PRINT REDIM _PRESERVE array(10 TO 20) FOR i = 10 TO 20 PRINT array(i); NEXT END

0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10


See also:



Navigation:
Keyword Reference - Alphabetical
Keyword Reference - By Usage
Main Wiki Page