Difference between revisions of "Metacommand"

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<center>'''Qbasic Metacommands'''</center>
 
<center>'''Qbasic Metacommands'''</center>
 
* Qbasic Metacommands are normally used at the program start and are in effect throughout the program.
 
* 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]].
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* Qbasic 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.
 
* [[$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 [[REDIM]] for changeable sizes! [[_PRESERVE]] preserves contents.
 
* [[$STATIC]] makes all arrays unchangeable in size. Use [[DIM]] only! [[ERASE]] and [[CLEAR]] do not affect the array size.
 
* [[$STATIC]] makes all arrays unchangeable in size. Use [[DIM]] only! [[ERASE]] and [[CLEAR]] do not affect the array size.
* '''Metacommands should have their own program line because they are commented.'''
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* '''Qbasic Metacommands should have their own program line because they are commented.'''
  
  

Revision as of 17:25, 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.
  • Qbasic 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! ERASE and CLEAR do not affect the array size.
  • Qbasic Metacommands should have their own program line because they are commented.


QB64 Metacommands
  • $INCLUDE can be used at the beginning or at the end of program SUB procedures. Referencing elsewhere creates an error!
  • Do NOT comment the QB64 specific Metacommands listed below!:
  • $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. Command uses no spacing!
  • $CONSOLE creates a console window which can be turned off with CONSOLE OFF. CONSOLE ON can only be used after OFF!
  • $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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