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 (1) then the result is on (1). * All other conditions return 0 (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}} {{PageExamples}} ''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 [[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 [[LONG]] variables for input values to prevent overflow errors. {{PageSeeAlso}} * [[OR]], [[XOR]], [[NOT]] {{text|(logical operators)}} * [[AND (boolean)]] * [[Binary]], [[Boolean]] {{PageNavigation}}