Difference between revisions of "Not"
From Free Pascal wiki
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end; | end; | ||
</pascal> | </pascal> | ||
| − | If you call OnesComplement(%10000000) then get %01111111 (%10000000 = 128 and %01111111 = 127). If you call OnesComplement(%00000111) then get 248 (248 = %11111000). | + | If you call OnesComplement([[Percent sign|%]]10000000) then get %01111111 (%10000000 = 128 and %01111111 = 127). If you call OnesComplement(%00000111) then get 248 (248 = %11111000). |
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* [[Byte]] | * [[Byte]] | ||
* [[Shortint]] | * [[Shortint]] | ||
| + | * [[And#Clear_a_bit| Clear_a_bit]] (bitwise example) | ||
Revision as of 15:58, 2 September 2008
Boolean operation
Not produces a value of true if original value is false.
Truth table
| A | Not A |
|---|---|
| false | true |
| true | false |
Bitwise operation
Bitwise not sets the bit to 1 if corresponding bit is 0, and to 0 if bit is 1.
Ones' complement
<pascal>
function OnesComplement (const aValue:byte):byte; begin result := Not AValue; end;
</pascal> If you call OnesComplement(%10000000) then get %01111111 (%10000000 = 128 and %01111111 = 127). If you call OnesComplement(%00000111) then get 248 (248 = %11111000).
<pascal>
function OnesComplement2 (const aValue:shortint):shortint; begin result := Not AValue; end;
</pascal>
If you call OnesComplement2(%00000010) then get %11111101 (%00000010 = 2 and %11111101 = -3 when type is shortint). If you call OnesComplement2(7) then get -8 (-8 = %11111000 when type is shortint and 7 = %00000111 ).
