The expression " x = (a,b); "

Question

In this comma-separated expression. Why doesn't the x gets value an instead of b?

int main() {

int a=20;
int b=100;
int x;
x=(a,b);

cout<<x;
}

Gives output: 100

Answer 1

The comma operator evaluates the left hand side, discards it, evaluates the right hand side, returns it.