Javascript 数组的总和和平均值

Question

我在获取两个数组的总和并在四舍五入时合并它们的平均值时遇到问题。

我不想硬编码，而是传递两个随机数组。
所以这是代码，但它不断返回NaN

function sumAverage(arr) {
  var result = 0;
  // Your code here
  // set an array
  arr = [];
  a = [];
  b = [];
  arr[0] = a;
  arr[1] = b;

  var sum = 0;

  // compute sum of elements in the array
  for (var j = 0; j < a.length; j++) {
    sum += a[j];
  }

  // get the  average of elements in the array
  var total = 0;
  total += sum / a.length;


  var add = 0;

  for (var i = 0; i < b.length; i++)
    add += b[i];

  var math = 0;
  math += add / b.length;

  result += math + total;

  Math.round(result);

  return result;
}
console.log(sumAverage([
  [2, 3, 4, 5],
  [6, 7, 8, 9]
]));

Answer 1

如果你想做得更实用一点，你可以这样做:

function sumAverage(arrays) {
  const average = arrays.reduce((acc, arr) => {
    const total = arr.reduce((total, num) => total += num, 0);
    return acc += total / arr.length;
  }, 0);
  
  return Math.round(average);
}

console.log('sum average:', sumAverage([[1,2,3], [4,5,6]]));