What is "int x = (a,b,c)"?

Question

I have never come across the statement of the form "int x = (a, b, c)" of type int until I took a quiz today about it. If a is 1, b 2, and c 3, then x is 3. What is this feature, how does it operate, and how is it useful?

Answer 1

After some searching I found part of my answer: it is an initializer much like int x = 3, int x = (3), int x (3), int x {3}, etc. It always sets the left-value to the last element of the initializer. I do not know why programmers would want to use it though when the other values are unused.