Difference between revisions of "Metacommand"
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Qbasic Metacommands
QB64 Metacommands
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| − | Qbasic '''Metacommands''' are program wide commands that start with $. | + | Qbasic '''Metacommands''' are program wide commands that start with $. QBasic requires them to be commented out. |
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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. | ||
| − | * [[$STATIC]] | + | * [[$STATIC]] makes all arrays {{KW|STATIC}} or unchangeable in size. Use {{KW|DIM}} only! |
| + | * [[$DYNAMIC]] allows larger arrays that are changeable in size. Use {{KW|REDIM}} for changeable sizes! [[_PRESERVE]] preserves contents. | ||
| + | * Metacommands should have their own program line when commented. | ||
<center>'''QB64 Metacommands'''</center> | <center>'''QB64 Metacommands'''</center> | ||
* QB64 does not require a comment or [[REM]] before any Metacommand. '''Do NOT comment QB64 specific Metacommands!''' | * QB64 does not require a comment or [[REM]] before any Metacommand. '''Do NOT comment QB64 specific Metacommands!''' | ||
| + | * [[$INCLUDE]] can be used at the beginning or at the end of program SUB procedures. Reference elsewhere create 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! | ||
| − | * | + | |
| − | + | * '''Do NOT comment or [[REM]] QB64 specific Metacommands! Comment or REM Qbasic ones only!''' | |
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Revision as of 16:33, 14 August 2012
Qbasic Metacommands are program wide commands that start with $. QBasic requires them to be commented out.
QB == Syntax ==
- 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 until $SCREENSHOW is used
- $SCREENSHOW 'displays the main QB64 program window throughout the program after $SCREENHIDE has been used
- 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.
- $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 when commented.
- 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. Reference elsewhere create 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!
- Do NOT comment or REM QB64 specific Metacommands! Comment or REM Qbasic ones only!
See also
