Difference between revisions of "Metacommand"

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::[[$CONSOLE]] 'creates a QB64 console window throughout the program
 
::[[$CONSOLE]] 'creates a QB64 console window throughout the program
  
::[[$SCREENHIDE]] 'hides the QB64 program window throughout the program until [[$SCREENSHOW]] is used
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::[[$SCREENHIDE]] 'hides the QB64 program window throughout the program
  
::[[$SCREENSHOW]] 'displays the main QB64 program window throughout the program after [[$SCREENHIDE]] has been used
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::[[$SCREENSHOW]] 'displays the main QB64 program window
  
  
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* Metacommands are always prefixed with $ and MUST be commented with an apostrophe or [[REM]].
 
* Metacommands are always prefixed with $ and MUST be commented with an apostrophe or [[REM]].
 
* [[$INCLUDE]] is always followed by a colon and the full text code file name is commented on both sides.
 
* [[$INCLUDE]] is always followed by a colon and the full text code file name is commented on both sides.
* [[$STATIC]] makes all arrays {{KW|STATIC}} or unchangeable in size. Use {{KW|DIM}} only!
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* [[$DYNAMIC]] allows larger arrays that are changeable in size. Use [[REDIM]] for changeable sizes! [[_PRESERVE]] preserves contents.
* [[$DYNAMIC]] allows larger arrays that are changeable in size. Use {{KW|REDIM}} for changeable sizes! [[_PRESERVE]] preserves contents.
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* [[$STATIC]] makes all arrays unchangeable in size. Use [[DIM]] only!
* Metacommands should have their own program line when commented.  
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* '''Metacommands should have their own program line because they are commented.'''
  
  
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* [[$INCLUDE]] can be used at the beginning or at the end of program SUB procedures. Referencing elsewhere creates an [[ERROR Codes|error]]!  
 
* [[$INCLUDE]] can be used at the beginning or at the end of program SUB procedures. Referencing elsewhere creates an [[ERROR Codes|error]]!  
 
* [[$CHECKING]]: OFF should only be used with '''errorless''' code where every CPU cycle counts! Use '''ON''' to re-enable event checking. Event checking can be turned OFF or ON throughout a program. Commands have no spaces and are '''NOT''' commented out!
 
* [[$CHECKING]]: OFF should only be used with '''errorless''' code where every CPU cycle counts! Use '''ON''' to re-enable event checking. Event checking can be turned OFF or ON throughout a program. Commands have no spaces and are '''NOT''' commented out!
 
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[[$SCREENHIDE]] 'hides the QB64 program window throughout the program until [[$SCREENSHOW]] is used.
 
* '''Do NOT comment or [[REM]] QB64 specific Metacommands! Comment or REM Qbasic ones only!'''
 
* '''Do NOT comment or [[REM]] QB64 specific Metacommands! Comment or REM Qbasic ones only!'''
  

Revision as of 16:41, 14 August 2012

Qbasic Metacommands are program wide commands that start with $. QBasic requires them to be commented out.


QB == Syntax ==

REM $INCLUDE: 'QB.BI' 'loads a reference file or library
REM $DYNAMIC 'enables resizing of array dimensions with REDIM
REM $STATIC 'arrays cannot be resized once dimensioned


QB64 == Syntax ==

$CHECKING:{OFF|ON} 'disables QB64 C++ event checking (no spaces)
$CONSOLE 'creates a QB64 console window throughout the program
$SCREENHIDE 'hides the QB64 program window throughout the program
$SCREENSHOW 'displays the main QB64 program window


Qbasic Metacommands
  • Qbasic Metacommands are normally used at the program start and are in effect throughout the program.
  • Metacommands are always prefixed with $ and MUST be commented with an apostrophe or REM.
  • $INCLUDE is always followed by a colon and the full text code file name is commented on both sides.
  • $DYNAMIC allows larger arrays that are changeable in size. Use REDIM for changeable sizes! _PRESERVE preserves contents.
  • $STATIC makes all arrays unchangeable in size. Use DIM only!
  • Metacommands should have their own program line because they are commented.


QB64 Metacommands
  • QB64 does not require a comment or REM before any Metacommand. Do NOT comment QB64 specific Metacommands!
  • $INCLUDE can be used at the beginning or at the end of program SUB procedures. Referencing elsewhere creates an error!
  • $CHECKING: OFF should only be used with errorless code where every CPU cycle counts! Use ON to re-enable event checking. Event checking can be turned OFF or ON throughout a program. Commands have no spaces and are NOT commented out!

$SCREENHIDE 'hides the QB64 program window throughout the program until $SCREENSHOW is used.

  • Do NOT comment or REM QB64 specific Metacommands! Comment or REM Qbasic ones only!



See also




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