Why the answer is 2 instead of 1 here?

Question

Fill in the blanks to print EVEN values from 0 to 20 using for a loop:
var x= 0
for ( ; x <= __; x +=_) {
document.write(x);
}

Answer 1

Because it is more efficient to increase <x> value by two. The next even number is always 2 number away from the first anyways. If <x> value was incremented by 1, then there will be more iterations needed, and there will be a need to check whether <x> was even or odd.

The same method can also be used to print odd values. But initial value of <x> must be an odd value too.

(Edit)
Please tag a relevant language -> Javascript

Answer 2

Thank you

Answer 3

No problem 👌