在像 C++ 这样的语言中 (a ^ (1 << b)) 实际上做了什么？

Question

I'm looking at this function,

int func(int a, int b){
    return (a ^ (1 << b)); 
}

What is actually going on? I understand that it's basically saying, " a XOR (2^b) ", that is, a xor 2 to the power of b. But beyond that what is actually happening, and why? I guess I'm looking for some sort of pattern in this formula.

Answer 1

This particular expression toggles the b-th bit of a.

This could be useful for example if you want to treat your int as a boolean array (or a bitmask), and negate the entry at position b.