QB64-PE/internal/help/Metacommand.txt

'''Metacommands''' are program wide commands that start with $.


==Legacy metacommands (QBasic/QuickBASIC)==
===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

===Description===
* QBasic metacommands are normally used at the program start and are in effect throughout the program.
* QBasic metacommands are always prefixed with <code>$</code> and MUST be commented with [[apostrophe|']] or [[REM]].
* [[$INCLUDE]] is always followed by a colon and the full filename must be included in single quotes.
* [[$DYNAMIC]] allows larger arrays that are changeable in size at runtime.
* [[$STATIC]] makes all arrays unchangeable in size.
* '''QBasic metacommands should have their own program line because they are commented.'''


==QB64 metacommands==
===Syntax===

:[[$ASSERTS]][:CONSOLE] 'enables assertions

:[[$CHECKING]]:{ON|OFF} 'disables QB64 C++ event and error checking (no spaces)

:[[$COLOR]]:{0|32} 'adds named color constants to the program

:[[$CONSOLE]][:ONLY] 'creates a QB64 console window throughout the program

:[[$ERROR]] message 'triggers a compilation error, useful inside $IF blocks

:[[$EXEICON]]:'iconfile.ico' 'embeds an .ICO file into the final executable (Windows only)

:[[$IF]]...[[$END IF]] 'precompiler conditional directive

:[[$LET]] variable = expression 'defines precompiler flags

:[[$NOPREFIX]] 'allows QB64 keywords without the leading <code>_</code>

:[[$RESIZE]]:{ON|OFF|STRETCH|SMOOTH} 'determines if re-sizing of the program screen by the user is allowed

:[[$SCREENHIDE]] 'hides the QB64 program window throughout the program

:[[$SCREENSHOW]] 'displays the main QB64 program window

:[[$VERSIONINFO]]:key=value[, ...] 'embeds version info metadata into the final executable (Windows only)

:[[$VIRTUALKEYBOARD]]:{ON|OFF} 'enables the virtual keyboard (Deprecated)


===Description===
* [[$INCLUDE]] can be used at the beginning or at the end of program SUB procedures.
* [[$ASSERTS]] enables the [[_ASSERT]] macro.
* [[$CHECKING]] '''OFF''' should only be used with '''errorless''' code where every CPU cycle counts! Use '''ON''' to re-enable event checking. Event checking can be turned OFF or ON throughout a program.
* [[$COLOR]] includes named color constants in a program.
* [[$CONSOLE]] creates a console window which can be turned off later with [[_CONSOLE]] OFF.
* [[$EXEICON]] embeds a designated icon file into the compiled EXE file. (Windows ONLY)
* [[$ERROR]] MESSAGE causes a compilation error whenever QB64 attempts to compile it, displaying MESSAGE to the user. This is useful if inside a $IF block, as the error can be conditional.
* [[$IF]]...[[$END IF]] allows selective inclusion of code in the final program.
* [[$LET]] used to set a flag variable for the precompiler.
* [[$NOPREFIX]] allows all QB64 functions and statements to be used without the leading underscore (_).
* [[$RESIZE]] allows a user to resize the program window. OFF is default.
* [[$SCREENHIDE]] hides the QB64 program window throughout the program until [[$SCREENSHOW]] is used.
* [[$VERSIONINFO]] adds metadata to Windows only binaries for identification purposes across the OS.
* [[$VIRTUALKEYBOARD]] turns the virtual keyboard ON or OFF for use in touch-enabled devices. (DEPRECATED)

* '''Do not comment out with [[apostrophe|']] or [[REM]] QB64-specific metacommands.'''


{{PageSeeAlso}}
* [[OPTION_BASE|OPTION BASE]], [[OPTION_EXPLICIT|OPTION _EXPLICIT]], [[OPTION_EXPLICITARRAY|OPTION _EXPLICITARRAY]]
* [[Statement]], [[Function (explanatory)]]
* [[REM]]
* [[DIM]], [[REDIM]]
* [[ON TIMER(n)]]




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