zizxzy
zizxzy
全排列js版本 ```js /** * @param {number[]} nums * @return {number[][]} */ var res = []; var permute = function (nums) { const backtrack = (nums, track, used) => { if...
```js // 防抖 const debounce = (func, wait) => { let timer = null; return function(){ const context = this; const args = arguments; clearTimeout(timer); setTimeout(() => { func.apply(context, args);...
函数的柯里化的应用 ```js const curry = (fn, args) => { const length = fn.length; let _args = args || []; return function () { let argArray = _args.slice(0); for (let i...
防抖和节流都用到了闭包
```js var addStrings = function (num1, num2) { let aLen = num1.length - 1; let bLen = num2.length - 1; let remainder = 0; let result = []; while (aLen...
```js const promiseAll = (promises) => { const newPromise = new Promise(function (resolve, reject) { if (!Array.isArray(promises)) reject(new Error('promises is not array')); const promiseLength = promises.length; let promiseResolveCount = 0;...
```js var arr = [{ id: 1, pid: '-1' }, { id: 11, pid: '1' }, { id: 12, pid: '1' }] const flatArrayToTree = (arr) => { let map...
```js Number.isInteger = function (value) { // es5的形式 return typeof value === 'number' && Number.isFinite(value) && Math.floor(value) === params; } ```
promise一共有三种状态：fulfilled（异步操作成功），rejected（异步操作失败），pending（异步操作未完成）。 通过catch捕获到reject之后，在catch后面可以继续执行then方法，catch返回的是一个新的promise实例，执行的是then方法的第一个回调函数。