多维数组降维 数组扁平化 flat,for循环

const flattenedArray = array.flat(Infinity);

function mFlat(arr) {
  let result = [];
  for (let i = 0; i < arr.length; i++) {
    if (Array.isArray(arr[i])) {
      result = result.concat(mFlat(arr[i]));
    } else {
      result.push(arr[i]);
    }
  }
  return result;
}
const array = [1, [2, [3, [4, 5]]], 6];
const flattenedArray = mFlat(array);