xiaowuge007

第6种继承方式，子类继承父类原型上的引用类型，还是存在篡改的可能，只是优化了组成继承中实例创建两次的问题

```javascript var count = 1; function ajax() { return new Promise((resolve, reject) => { setTimeout(() => { if (count > 4) { resolve('success') } else { count++; reject('error') } },...

```javascript function multiRequest(urls, maxNum, callback) { var arr = []; var count = 0; for (let i = 0; i < maxNum; i++) { ajax(i) } function ajax(i) { if...

```javascript function normalize(str) { let res = str.match(/\[(.+?)\]/); let p = res ? res[1] : str; let arr = p.split('['); var obj = {}; var cur = obj; for (let...

``` var arr = ['a','b','c','c','b','b','a','c','b'] arr.filter(res => res === 'a').concat(arr.filter(res => res === 'b').concat(arr.filter(res => res === 'c'))); ```

``` let arr1 = [1,2,3,4,5]; let arr2 = [2,4,6,8,7]; let arr3 = [3,2,5,6,9,10,2]; let arr4 = [10,23,4,56,1,2]; let arr5 = [1,4,8,70,2]; function fn(...arg) { let a = new Set(arg[0]); for(let...

``` var entry = { 'a.b.c.dd': 'abcdd', 'a.d.xx': 'adxx', 'a.e': 'ae', 'text': 'text' } function go(obj,res) { for(key in obj){ let arr = key.split('.'); if(arr.length > 1){ res[arr[0]] = res[arr[0]]...

```javascript //多加一个参数不就可以了吗 function print(n){ setTimeout(() => { console.log(n); },1000, Math.floor(Math.random() * 1000)); } for(var i = 0; i < 100; i++){ print(i); } ```

`javascript function firstString(str) { let map = new Map(); let obj = {} for(let i = 0;i

```javascript function symmetryTree_2(root) { if(!root){return false} if(!root.left && !root.right){return true} if(!root.left || !root.right){return false} if(root.left && root.right){ let arr = [root.left,root.right]; while (arr.length>0){ let left = arr.shift(); let right =...