Difference between revisions of "Xor"
From Free Pascal wiki
Jump to navigationJump to search (add footer, cat) |
|||
| (9 intermediate revisions by 7 users not shown) | |||
| Line 1: | Line 1: | ||
| + | {{Xor}} | ||
| + | Back to [[Reserved words]]. | ||
| + | |||
| + | The '''xor''' [[Operator|{{HL|operator}}]] compares two [[Boolean|{{HL|boolean}}]] values, and returns true if and only if one of them is true. | ||
| + | |||
| + | = Boolean operation = | ||
| + | |||
Exclusive or ('''xor''') results in a value of [[True|true]] if and only if exactly one of the operands has a value of true. | Exclusive or ('''xor''') results in a value of [[True|true]] if and only if exactly one of the operands has a value of true. | ||
| + | == Truth table == | ||
| + | |||
| + | {| class="wikitable" | ||
| + | |- | ||
| + | ! A !! B !! A xor B | ||
| + | |- | ||
| + | | false || false | ||
| + | |style="background: #eeeeee" | false | ||
| + | |- | ||
| + | | false || true | ||
| + | |style="background: #eeeeee" | true | ||
| + | |- | ||
| + | | true || false | ||
| + | |style="background: #eeeeee" | true | ||
| + | |- | ||
| + | | true || true | ||
| + | |style="background: #eeeeee" | false | ||
| + | |} | ||
= Bitwise operation = | = Bitwise operation = | ||
| Line 8: | Line 33: | ||
== Toggle a bit == | == Toggle a bit == | ||
| − | < | + | <syntaxhighlight lang=pascal> |
function ToggleBit(const AValue,ABitNumber:integer):integer; | function ToggleBit(const AValue,ABitNumber:integer):integer; | ||
begin | begin | ||
result := AValue xor 1 shl ABitNumber; | result := AValue xor 1 shl ABitNumber; | ||
end; | end; | ||
| − | </ | + | </syntaxhighlight> |
If you call ToggleBit(11,0) then get 10. If you call ToggleBit(10,2) then get 14. | If you call ToggleBit(11,0) then get 10. If you call ToggleBit(10,2) then get 14. | ||
| − | + | {{Logical operators}} | |
| − | * [[ | + | * [[Variable_parameter#XOR swap| XOR swap]] |
* [[Const]] | * [[Const]] | ||
* [[Function]] | * [[Function]] | ||
* [[Integer]] | * [[Integer]] | ||
| + | |||
| + | [[Category:Code]] | ||
| + | [[Category:Operators]] | ||
Revision as of 23:45, 16 October 2020
│
Deutsch (de) │
English (en) │
suomi (fi) │
français (fr) │
русский (ru) │
Back to Reserved words.
The xor operator compares two boolean values, and returns true if and only if one of them is true.
Boolean operation
Exclusive or (xor) results in a value of true if and only if exactly one of the operands has a value of true.
Truth table
| A | B | A xor B |
|---|---|---|
| false | false | false |
| false | true | true |
| true | false | true |
| true | true | false |
Bitwise operation
Bitwise xor sets the bit to 1 where the corresponding bits in its operands are different, and to 0 if they are the same.
Toggle a bit
function ToggleBit(const AValue,ABitNumber:integer):integer;
begin
result := AValue xor 1 shl ABitNumber;
end;
If you call ToggleBit(11,0) then get 10. If you call ToggleBit(10,2) then get 14.
| operators |
|
|---|---|
| see also |
|
