Why is cout within the while condition parenthesis?

Question

int x = 5;
while (x && cout << x--);

Why is cout within the while condition parenthesis?
What is the x left of the logical AND operator comparing to?
How come the output is 54321? Where would I begin to figure out this output?

Answer 1

If we want to print a variables when checking conditions we declare like that with in parenthesis.
This loop print x - value and then decrement x. So that 5 then 4 3 2 1. When reach 0 the conditions fails loop was stop.

Answer 2

I'm guessing the value of <x> is the one considered as loop condition here. As we noticed the loop stops when <x> value reaches zero (a falsey value). The short-circuit evaluation of logical AND only evaluates the RHS (cout << x--) while <x> value not equals zero (cmiiw).

Answer 3

Ipang Could it also be that we're evaluating it like 'while (X&&Y)' where Y is cout << x--, an action item that is always true?

Of course, when either X or Y becomes zero, (X&&Y) would evaluate to false.