问题
Can anyone explain this operator with a good example?
I know what this operator is. I mean a real-life example.
回答1:
It is an implementation of the the logical operation exclusive disjunction
http://en.wikipedia.org/wiki/Exclusive_or
Exclusive disjunction is often used for bitwise operations. Examples:
- 1 xor 1 = 0
- 1 xor 0 = 1
- 0 xor 1 = 1
- 0 xor 0 = 0
- 1110 xor 1001 = 0111 (this is equivalent to addition without carry)
As noted above, since exclusive disjunction is identical to addition modulo 2, the bitwise exclusive disjunction of two n-bit strings is identical to the standard vector of addition in the vector space (Z/2Z)^4.
In computer science, exclusive disjunction has several uses:
- It tells whether two bits are unequal.
- It is an optional bit-flipper (the deciding input chooses whether to invert the data input).
- It tells whether there is an odd number of 1 bits ( is true iff an odd number of the variables are true).
(and a whole ton of other uses)
回答2:
For example, like this:
var result = a ^ b;
result a b
--------------------------------
true true false
true false true
false true true
false false false
回答3:
For "exclusive or" to evaluate to true one and only one operand has to be true.
foo ^ bar
is equivalent to
(foo && !bar) || (!foo && bar)
回答4:
When using XOR, the statement only evaluates to true if only ONE of the compared statements is true. So:
bool foo = true;
bool bar = false;
if (foo ^ bar) { bar = true; // this evaluates to true }
if (foo ^ bar) { // This evaluates to false, since both statements are now true. }
回答5:
XOR is a common boolean operator and has nothing unique to it in C#. I suggest reading a little about boolean algebra to learn what it is used for with 1 bit, then check what you get when you do (a XOR b) XOR b with any two numbers or characters a and b.
回答6:
A programming language's reference is always the best place to look for the definitions of operators.
In this case, MSDN is the most appropriate definition for a C# operator.
According to the documentation:
Binary ^ operators are predefined for the integral types and bool. For integral types, ^ computes the bitwise exclusive-OR of its operands. For bool operands, ^ computes the logical exclusive-or of its operands; that is, the result is true if and only if exactly one of its operands is true.
An example is also listed.
来源：https://stackoverflow.com/questions/6422329/what-is-c-sharp-exclusive-or-usage