got confused with JSChallange, decrement in WhileLoop

Question

i got this question where
var a;
var b = 0;
a = 20;
a = --a;
while(a > a--){
b++;
}
document.write(b);
the result that i got is 0, why? is the 'b' not being processed by the while loop? or its just a trap question?
Or is it because a>a-- is 19 > 19 which is returned false so that the looping do not runing thus the 'b' is back to the first value?
Am I clear enough to describe my question? I'm afraid you don't understand with what I'm trying to ask

Answer 1

I would assume it's because 19 == 19. Since it's a post decrement, the variable 'a' won't be affected until after, so you got it. It just won't trigger the while loop

Answer 2

oh ok i understand now, tysm for your explanation

Answer 3

Slick
so its true that the WHILE looping do not asign the b++ to the 'b' because the condition that the WHILE meet is 'false' And the value of 'b' is still 0.

Answer 4

Yeah, check this one
https://code.sololearn.com/WyJd9J0D78Ct/?ref=app