用JavaScript 通过循环按顺序为一个5×5的二维数组arr赋1到25的自然数,然后输出该数组的左下半三角的和?var z = 1var total = 0var arr = []for (var i = 0 i < 5 i++) {arr[i] = []for (var j = 0 j < 5 j++2023-02-21JavaScript210