How to swap 2 variables value?

Question

How to swap value of 2 variables without add 3rd variable ??

Answer 1

a += (b - (b = a));

works fine, and it's only 1 line of code!!😀

Answer 2

a = a + b;
b = b - a;
b = -b;
a = a - b;

Answer 3

@Kamil, @Yan: Great simplification of code. Watch out when the variables don't have infinite precision, though –you could be lead to accuracy issues.

Answer 4

@Kamil, great and simple,
@Kamil @Yan Markov, thanks...