Why output is 17 17

Question

int main() {
int a=0,b=0;
while (a<7, b<17) {
a++; b++;
}
printf ("%d\n%d", a,b);
return 0;
}

Answer 1

How output is 17

Answer 2

Thanks brother

Answer 3

Comma operator between the two conditions `a < 7` and `b < 17` works by evaluating and then discarding its left-hand operand. So in your case, only `b < 17` is eventually used as loop condition.

https://en.m.wikipedia.org/wiki/Comma_operator

Hth, cmiiw

Answer 4

Did you even read the link in my previous post? it should explain how and why it happens.

Initially, both <a> and <b> are zero.
Then you setup a loop, the loop has two conditions `a < 7` and `b < 17`.

Since you put Comma operator between the two `if` conditions, the left-hand operand `a < 7` be evaluated and then discarded (abandoned, ignored).

Next the right-hand operand `b < 17` is evaluated, and this is the condition that decides when the loop should continue or stop. The loop should continue *while* <b> value is less than 17.

Inside the loop body you increase value of <a> and <b>, and the instruction within loop body is repeated following the condition `b < 17`

When the loop exits the value of <a> and <b> would be both 17. And that's how you have '17 17' in output.