Why the output of this code is 337 (JavaScript)?

Question

function mlt(a, b) {
if (!(a&&b)) {
return 0;
} else if (b == 1) {
return a;
} else {
return (a + mlt(a, b - 1));
}
}
document.write(mlt(3, 11));
document.write(mlt(7, 1));

Answer 1

This function is used for multiplying numbers. The first case with 3, 11 => enter in the else condition until b equals 1 => 3 + mlt (3, 10) + 3 +mlt (3, 9) + ... + 3 + mlt(3, 1) and return the result => 11*3 = 33. The same is with parameters 7, 1 => result 7*1 =7. So the final result is 337. Hope it helps you :)

Answer 2

It's an example for recursion. Because of document.write there's no line break between 33 and 7.

Answer 3

TheWhiteCat thanks very much