What is the logic ?

Question

Guess the output of the following c++ code.

#include<iostream>
using namespace std;
int main(){

int x=2,y=4,z=6,q;
q = (x,y,z);
cout<<q;
return 0;
}

The output comes as 6.
Can anyone help to to find out how ?

Answer 1

comma operator evaluates left values and returns last value
https://stackoverflow.com/q/52550/9132046

Answer 2

Alex Schmidt It's only useful when first operand has a side effect. It doesn't have many use cases but you can see them here
https://en.m.wikipedia.org/wiki/Comma_operator#Examples
https://en.m.wikipedia.org/wiki/Comma_operator#Uses

Answer 3

«The comma operator links two expressions into one and guarantees that the leftmost expression is evaluated first. It is typically used to include more information in a for loop control expression. The value of the whole expression is the value of the right-hand expression.»
C Primer Plus, By Stephen Prata

Answer 4

In this case it effectively means q=z.

Answer 5

Mert, why is that usefull?
I mean I could always type q = z easy and simple

Answer 6

Thank you

Answer 7

Exactly Sonic

Answer 8

Z is the last value initialized to q , thats why output is 6