我已经用java实现了合并排序，它似乎工作正常。为了创建合并排序算法的可视化表示，我尝试将这段代码转换为javascript，但我无法让这段代码正常工作。
以下是我的java实现的代码：
'''

public class MergeSort {

    public void merge(int[] arr, int[] tmpArr, int lo, int mid, int hi) {

        for (int k = lo; k <= hi; k++) {  // first we copy over the array to our tmp array
            tmpArr[k] = arr[k];
        }

        int left = lo;         // keeps index of left side of tmp array
        int right = mid + 1;    // keeps index of right side of tmp array

        for (int l = lo; l <= hi; l++) {  // l keeps the index of the sorted array
            if (left > mid) {               // will merge remaining values in right side of array
                arr[l] = tmpArr[right];
                right++;
            } else if (right > hi) {         // will merge remaining values in left side of array
                arr[l] = tmpArr[left];
                left++;
            } else if (tmpArr[left] < tmpArr[right]) {  // checks if value in left array is less than value in right array
                arr[l] = tmpArr[left];
                left++;
            } else {
                arr[l] = tmpArr[right];
                right++;
            }
        }
    }

    public void sort(int[] arr) {
        int[] tmpArr = new int[arr.length];
        sort(arr, tmpArr, 0, arr.length - 1);
    }

    public void sort(int[] arr, int[] tmpArr, int lo, int hi) {
        if (lo >= hi) {
            return;
        }

        int mid = lo + ((hi - lo) / 2);
        sort(arr, tmpArr, lo, mid);
        sort(arr, tmpArr, mid + 1, hi);
        merge(arr, tmpArr, lo, mid, hi);
    }
}

'''
以下是我的javascript实现：
'''

function merge(arr, tmpArr, lo, mid, hi) {
    tmpArr = arr.slice(lo, hi + 1); // copy array over to tmp array

    left = lo; // keeps index of left side of tmp array
    right = mid + 1; // keeps index of right side of tmp array

    for (index = lo; index <= hi; index++) { // index keeps the index of the sorted array
        if (left > mid) { // will merge remaining values in right side of array
            arr[index] = tmpArr[right];
            right++;
        } else if (right > hi) { // will merge remaining values in left side of array
            arr[index] = tmpArr[left];
            left++;
        } else if (tmpArr[left] < tmpArr[right]) { // checks if value in left array is less than value in right array
            arr[index] = tmpArr[left];
            left++;
        } else if (tmpArr[right] < tmpArr[left]) {
            arr[index] = tmpArr[right];
            right++;
        }
    }
}

function sort(arr, tmpArr, lo, hi) {
    if (lo >= hi) { // gets rid of edge case where array has 1 element
        return;
    }

    mid = Math.floor(lo + ((hi - lo) / 2));
    sort(arr, tmpArr, lo, mid);
    sort(arr, tmpArr, (mid + 1), hi);
    merge(arr, tmpArr, lo, mid, hi);
}

function mergeSort(arr) {
    tmpArr = [];
    sort(arr, tmpArr, 0, arr.length - 1);
}

'''
我花了几个小时来调整这段代码，并在代码中插入print语句，但我似乎不明白为什么它可以在java而不是javascript中工作。我对java的精通程度比javascript要高得多，所以我想我可能遗漏了一些东西。任何帮助都将不胜感激，提前谢谢你。