手写reduce（JavaScript）

Array.prototype.myReduce = function (cb, initialValue) {
  const array = this//获取数组
  let acc = initialValue || array[0]//acc相当于pre
  const startIndex = initialValue ? 0 : 1
  for (let i = startIndex; i < array.length; i++) {
    const cur = array[i]
    acc = cb(acc, cur, i, array)
  }
  return acc
}

参考链接：blog.csdn.net/Beijiyang99…