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42 lines
1.7 KiB
Plaintext
42 lines
1.7 KiB
Plaintext
{{DISPLAYTITLE:_LIMIT}}
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The [[_LIMIT]] statement sets the loop repeat rate of a program to so many per second, relinquishing spare CPU cycles to other applications.
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{{PageSyntax}}
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: [[_LIMIT]] {{Parameter|framesPerSecond!}}
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* The {{Parameter|framesPerSecond!}} [[SINGLE]] parameter value adjusts the loops per second of a program loop. '''Do not use negative values.'''
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* The loop code is executed before the loop is delayed. Loop cycles below once per second may delay program [[_EXIT]]s.
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* _LIMIT measures its interval from the previous time that it was called and minor adjustments are automatically made to ensure that the number of times a loop is repeated is correct overall.
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* Loop cycle rates of 1000 or less can '''significantly reduce CPU usage''' in programs.
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* Do not use it to limit a loop to '''less than once every 60 seconds'''(.0167) or an [[ERROR Codes|ILLEGAL FUNCTION CALL error]] will occur.
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* Do not use _LIMIT as a timing delay outside of loops. Use [[_DELAY]] instead.
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* Use _LIMIT to slow down old QBasic program loops that run too fast and use too much CPU.
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{{PageExamples}}
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''Example:'' Limits loop execution to 30 frames per second and limits the program's CPU usage.
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{{CodeStart}} '' ''
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{{Cl|PRINT}} "To Quit press ESC key!"
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{{Cl|DO}}
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{{Cl|_LIMIT}} 30
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{{Cl|PRINT}} {{Cl|CHR$}}(26);
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{{Cl|IF...THEN|IF}} {{Cl|INKEY$}} = {{Cl|CHR$}}(27) {{Cl|THEN}} {{Cl|EXIT DO}} '' ''
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{{Cl|LOOP}}
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{{CodeEnd}}
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{{OutputStart}}
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To Quit press ESC key!
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→→→→→→→→→→→→→→→→→→→→
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{{OutputEnd}}
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:''Note:'' In the above example, _LIMIT has to be within the loop.
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{{PageSeeAlso}}
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* [[_DELAY]]
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* [[TIMER]], [[ON TIMER(n)]]
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* [[SLEEP]]
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{{PageNavigation}}
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