mirror of
https://github.com/QB64-Phoenix-Edition/QB64pe.git
synced 2024-07-26 14:25:53 +00:00
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.
78 lines
2.6 KiB
Plaintext
78 lines
2.6 KiB
Plaintext
The logical '''AND''' numerical operator compares two values in respect of their bits. If both bits at a certain position in both values are set, then that bit position is set in the result.
|
|
|
|
|
|
{{PageSyntax}}
|
|
:{{Parameter|result}} = '''{{Parameter|firstvalue}} AND {{Parameter|secondvalue}}'''
|
|
|
|
|
|
|
|
{{PageDescription}}
|
|
* AND compares the bits of the {{Parameter|firstvalue}} against the bits of the {{Parameter|secondvalue}}, the result is stored in the {{Parameter|result}} variable.
|
|
* If both bits are on or binary 1 then the result is on or 1.
|
|
* All other conditions return 0 or the bit is off.
|
|
* AND is often used to see if a bit is on by comparing a value to an exponent of 2.
|
|
* Can turn off a bit by subtracting the bit on value from 255 and using that value to AND a byte value.
|
|
|
|
|
|
{{Template:LogicalTruthTable}}
|
|
|
|
|
|
''Example 1:''
|
|
{{WhiteStart}}
|
|
101
|
|
AND
|
|
011
|
|
-----
|
|
001
|
|
{{WhiteEnd}}
|
|
|
|
:The 101 bit pattern equals 5 and the 011 bit pattern equals 3, it returns the bit pattern 001 which equals 1. Only the Least Significant Bits(LSB) match. So decimal values 5 AND 3 = 1.
|
|
|
|
|
|
''Example 2:''
|
|
{{WhiteStart}}
|
|
11111011
|
|
AND
|
|
11101111
|
|
----------
|
|
11101011
|
|
{{WhiteEnd}}
|
|
:Both bits have to be set for the resulting bit to be set. You can use the AND operator to get one byte of a two byte integer this way:
|
|
|
|
:::::firstbyte = twobyteint AND 255
|
|
|
|
:Since 255 is 11111111 in binary, it will represent the first byte completely when compared with AND.
|
|
|
|
:To find the second(HI) byte's decimal value of two byte {{KW|INTEGER}}s use: secondbyte = twobyteint \ 256
|
|
|
|
|
|
''Example 3:'' Finding the binary bits on in an [[INTEGER]] value.
|
|
{{CodeStart}}
|
|
|
|
DO
|
|
{{Cl|INPUT}} "Enter Integer value from -32768 to 32767 (Enter quits): ", INTvalue&
|
|
IF INTvalue& < -32768 OR INTvalue& > 32767 OR INTval& = 0 THEN {{Cl|EXIT DO}}
|
|
{{Cl|FOR...NEXT|FOR}} exponent = 15 {{Cl|TO}} 0 {{Cl|STEP}} -1
|
|
{{Cl|IF...THEN|IF}} (INTvalue& {{Cl|AND}} 2 ^ exponent) {{Cl|THEN}} {{Cl|PRINT}} "1"; {{Cl|ELSE}} {{Cl|PRINT}} "0";
|
|
{{Cl|NEXT}}
|
|
PRINT " "
|
|
LOOP UNTIL INTvalue& = 0 'zero entry quits
|
|
|
|
{{CodeEnd}}
|
|
|
|
:Example output for 6055.
|
|
{{OutputStart}}
|
|
0001011110100111
|
|
{{OutputEnd}}
|
|
::''Note:'' The value of 32767 sets 15 bits. -1 sets all 16 bits. Negative values will all have the highest bit set. Use {{KW|LONG}} variables for input values to prevent overflow errors!
|
|
|
|
|
|
|
|
|
|
{{PageSeeAlso}}
|
|
*{{KW|OR}} (operator), {{KW|XOR}} (operator), {{KW|NOT}} (operator)
|
|
*{{KW|AND (boolean)}}
|
|
*[[Binary]], [[Boolean]]
|
|
|
|
|
|
{{PageNavigation}} |