Comma operator in FOR loop, how does that work?

Question

Can anyone please explain the comma operator in FOR statement?

function funct_1(c){
    for (var a = x, e = y; 0 < c; ){ 
         var p = c/2;
         var c = c/10; // wtf, it is already defined as function argument!!
    }
}

Also, the last statement like "a++" seems to be missing. I have never seen anything like this. what does that mean?

Answer 1

The comma just adds separation for multiple declarations. In other words, your for loop is setting a equal to x, as well as e equal to y.

As for the lack of the increment statement, the fact that it is missing just means that the for loop won't explicitly increment any variable.