mongonice

```js let nums1 = [1, 2, 2, 1], nums2 = [2, 2]; let common = nums1.filter(item => nums2.includes(item)) console.log(common) ```

```js Number.prototype.add = function (num) { return this + num } Number.prototype.minus = function (num) { return this - num } console.log((5).add(3).minus(2)) // 6 ```

**promise方法** ```js function sleep(time) { return new Promise(resolve => { setTimeout(() => { resolve() }, time) }) } sleep(1000).then((data) => { // do something }) ``` **async/await方法** ```js async function...

一开始真没转过弯来，实践了一下，才明白过来，顺便在这里记录一下： 先让我改造一下： ```js function changeObjProperty(o) { // o这个形参实际可以写成var o = webSite o.siteUrl = "http://www.baidu.com"; // 偷偷添加一行代码，此时website和o指向同一个堆地址 // website.siteUrl = "http://www.baidu.com"; o = new Object() // 相当于 o = {}, o...

[挺不错的](https://blog.csdn.net/u010429424/article/details/77340422)