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6e01fc8dce
Added new _STRCMP and _STRICMP commands for quick string comparisons. Cleaned up QB64 to finish removing the QUI (quick user insert) code and folders. Altered UCASE and LCASE routines to be faster in some situations for us.
46 lines
1.4 KiB
Plaintext
46 lines
1.4 KiB
Plaintext
'''NOT''' is a [[Boolean]] logical operator that will change a False statement to a True one and vise-versa.
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{{PageSyntax}}
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:: True = -1: False = '''NOT''' True
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* In Qbasic, True = -1 and False = 0 in boolean logic and evaluation statements.
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* NOT evaluates ONE value and returns the opposite. Yes, NOT 0 = -1 in Basic.
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* Often called a negative logic operator, it returns the opposite of a value as true or false.
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{{Template:RelationalTable}}
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{{Template:LogicalTruthTable}}
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''Example 1:'' Alternating between two conditions in a program loop.
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{{CodeStart}}
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{{Cl|DO}}
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switch = {{Cl|NOT}} switch '{{Cl|NOT}} changes value from -1 to 0 and vice-versa
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{{Cl|LOCATE}} 10, 38
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{{Cl|IF}} switch {{Cl|THEN}} {{Cl|PRINT}} "True!" {{Cl|ELSE}} {{Cl|PRINT}} "False"
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{{Cl|SLEEP}}
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k$ = {{Cl|INKEY$}}
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{{Cl|LOOP}} {{Cl|UNTIL}} k$ = {{Cl|CHR$}}(27) ' escape key quit
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{{CodeEnd}}
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''Example 2:'' Reading a file until it reaches the End Of File.
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{{CodeStart}}
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DO WHILE NOT EOF(1)
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INPUT #1, data1, data2, data3
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LOOP '' ''
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{{CodeEnd}}
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:''Explanation:'' [[EOF]] will return 0 until a file ends. NOT converts 0 to -1 so that the loop continues to run. When EOF becomes -1, NOT converts it to 0 to end the loop.
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''See also:''
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*[[DO...LOOP]], [[WHILE...WEND]],
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*[[IF...THEN]], [[AND]], [[XOR]]
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*[[OR]], [[Binary]], [[Boolean]]
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*[[Mathematical Operations]]
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{{PageNavigation}} |