Difference between revisions of "And"
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== Is power of two == | == Is power of two == | ||
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function IsPowerOfTwo( const aValue : longint ): boolean; | function IsPowerOfTwo( const aValue : longint ): boolean; | ||
var | var | ||
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result := b; | result := b; | ||
end; | end; | ||
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If you call IsPowerOfTwo(4) then get true. If you call IsPowerOfTwo(5) then get false . | If you call IsPowerOfTwo(4) then get true. If you call IsPowerOfTwo(5) then get false . | ||
Revision as of 14:48, 24 March 2012
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Boolean operation
And produces a value of true if and only if both of its operands are true.
Truth table
| A | B | A and B |
|---|---|---|
| false | false | false |
| false | true | false |
| true | false | false |
| true | true | true |
Bitwise operation
Bitwise and sets a bit to 1 if and only if all of the corresponding bits in its operands are 1.
Is power of two
function IsPowerOfTwo( const aValue : longint ): boolean;
var
x : longint;
b : boolean;
begin
b := false;
if aValue <> 0 then
begin
x := aValue - 1;
x := x and aValue;
if x = 0 then b := true;
end;
result := b;
end;If you call IsPowerOfTwo(4) then get true. If you call IsPowerOfTwo(5) then get false .
