1. 递归的方法实现
// 使用递归的方法实现let arr = [1, 3, 5, [24, 52], 2, [23, [3, [6], 7], 2]]function _flat(arr, deepth) {if (!Array.isArray(arr) || deepth <= 0) {return arr}return arr.reduce((prev, cur) => {if (typeof cur === "object") {return prev.concat(_flat(cur, deepth - 1))} else {return prev.concat(cur)}}, [])}console.log(_flat(arr, 4));
