function pow(x, n) {
  if (n == 1) {
    return x;
  } else {
    return x * pow(x, n - 1);
  }
}

alert( pow(2, 3) ); // 8

I don't know how pow (x, n-1) works.

If we repeat it until if (n == 1), isn't the return value 2?