Climbing Stairs LeetCode solution in JavaScript

1
var climbStairs = function (n) {
2
  if (n < 4) return n;
3
  let fib = [1, 1];
4
  for (let i = 2; i <= n; i++) {
5
    fib[i] = fib[i - 1] + fib[i - 2];
6
  }
7
  return fib[n];
8
};