Question

I am looking for some explanations regarding the behavior of the following code:

int a = 1;
int b = (4,5,6);
cout<<a+b;

Why is it that b takes the last value 6?

EDIT: Sorry, I made the wrong example, thanks to all for the explaining how b gets the value 6.

Answer 1

I’m sorry, your code is not syntactically valid.

2 and 3 should be declaration names. Like c and d.

To use the comma operator, you have to parenthesize 1, 2, 3.

I will forgive you this accident and continue to explain.

If you use the comma operator, which is used as operand1 , operand2, it will give you the value (or lvalue) of operand2. So you initialize b to 6 (as in (4, 5), 6, since the comma operator is left associative).