Merge Sorted Array

You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number of elements in nums1 and nums2 respectively.

Merge nums1 and nums2 into a single array sorted in non-decreasing order.

The final sorted array should not be returned by the function, but instead be stored inside the array nums1. To accommodate this, nums1 has a length of m + n, where the first m elements denote the elements that should be merged, and the last n elements are set to 0 and should be ignored. nums2 has a length of n.

function mergeSortedArr(nums1, m, nums2, n) {
    let i = m - 1;
    let j = n - 1;
    let k = m + n - 1;

    while (i >= 0 && j >= 0) {
        if (nums1[i] > nums2[j]) {
            nums1[k] = nums1[i];
            i--;
        } else {
            nums1[k] = nums2[j];
            j--;
        }
        k--;
    }

    while ( j >= 0) {
        nums1[k] = nums2[j];
        j--;
        k--;
    }
    return nums1;
}

console.log(mergeSortedArr([1,2,3], 3, [1,2,2], 3));