Difference between revisions of "Metacommand"

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''Syntax:''
 
''Syntax:''
  
::REM {{KW|$INCLUDE}}: 'QB.BI' 'loads a referance file or library
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::REM {{KW|$INCLUDE}}: 'QB.BI' 'loads a reference file or library
  
::REM {{KW|$DYNAMIC}} 'enables resizing of array dimensions
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::REM {{KW|$DYNAMIC}} 'enables resizing of array dimensions with REDIM
  
::REM {{KW|$STATIC}} 'arrays cannot be resized
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::REM {{KW|$STATIC}} 'arrays cannot be resized once dimensioned
  
 
::$CHECKING: OFF 'disables QB64 C++ event checking
 
::$CHECKING: OFF 'disables QB64 C++ event checking
  
  
* $CHECKING: OFF should only be used with '''errorless''' code where every CPU cycle counts! Use ON to re-enable event checking.
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* '''$CHECKING: OFF''' should only be used with '''errorless''' code where every CPU cycle counts! Use '''ON''' to re-enable event checking.
* Event $CHECKING is '''NOT''' commented out!
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* '''QB64''' event $CHECKING is '''NOT''' commented out!
* Metacommands are normally used at the program start and are in effect throughout the program.
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* '''Qbasic''' Metacommands are normally used at the program start and are in effect throughout the program.
 
* {{KW|$INCLUDE}} can be used at the beginning or at the end of program SUB procedures. Placing the reference elsewhere creates a QB64 compiler error!  
 
* {{KW|$INCLUDE}} can be used at the beginning or at the end of program SUB procedures. Placing the reference elsewhere creates a QB64 compiler error!  
 
* $STATIC makes all arrays {{KW|STATIC}} or unchangeable in size. Use {{KW|DIM}} only!
 
* $STATIC makes all arrays {{KW|STATIC}} or unchangeable in size. Use {{KW|DIM}} only!
* $DYNAMIC allows larger arrays that are changeable in size. Use {{KW|REDIM}} for changeable sizes!
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* $DYNAMIC allows larger arrays that are changeable in size. Use {{KW|REDIM}} for changeable sizes! [[_PRESERVE]] preserves contents.
 
* Metacommands should have their own program line since they are commented out.
 
* Metacommands should have their own program line since they are commented out.
  

Revision as of 22:02, 9 September 2010

Qbasic Metacommands are commands that are commented out and start with $.


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
$CHECKING: OFF 'disables QB64 C++ event checking


  • $CHECKING: OFF should only be used with errorless code where every CPU cycle counts! Use ON to re-enable event checking.
  • QB64 event $CHECKING is NOT commented out!
  • Qbasic Metacommands are normally used at the program start and are in effect throughout the program.
  • $INCLUDE can be used at the beginning or at the end of program SUB procedures. Placing the reference elsewhere creates a QB64 compiler error!
  • $STATIC makes all arrays STATIC or unchangeable in size. Use DIM only!
  • $DYNAMIC allows larger arrays that are changeable in size. Use REDIM for changeable sizes! _PRESERVE preserves contents.
  • Metacommands should have their own program line since they are commented out.


See also:

DIM, REDIM

ON TIMER (n)




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