## 递归实现 ``` let returnArr = []; let arr = []; const getArray = (array = []) => { for (let i = 0; i < array.length; i++) { let num = array.splice(i, 1)[0]; arr.push(num); if (array.length <= 0) { returnArr.push([...arr]); } getArray(array); array.splice(i, 0, num); arr.pop(); } return returnArr } getArray([1, 2, 3, 4]); ```