weichuyong_的博客

ES7包含const arr = [1, 2, 3, 4, 5]console.log(arr.includes(40)) // arr是否包含40平方// console.log(Math.pow(2, 5)) // 2的5次平方console.log(2 ** 5) // es7ES8async关键字将方法变成promise对象async function firstAsunc () { return 27}console.log(firstAsunc())

迭代器遍历对象let authors = { allAuthors: { fiction: ['Agla', 'Skks', 'LP'], scienceFiction: ['Neal', 'Arthru', 'Ribert'], fantasy: ['J.R.Tole', 'J.M.R', 'Terry P.K'] }, Addres: []}遍历规范authors[Sysbol.iterator] = function () { return {

代理let o = { name: 'xiaoming', price: 190}let d = new Proxy(o, { get (target, key) { if (key === 'price') { return target[key] + 20 } else { return target[key] } }})console.log(d.price, d.name)Object.defineProperty():

异步操作异步处理不用阻塞当前线程来等待处理完成，而是允许后续操作，直至其它线程将处理完成，并回调通知此线程。做了一系列的操作后告诉主机默认异步js是单线程，先加载的1.js文件，然后发生异步操作不等待js文件的运行先让test运行function loadScript (src) { let script = document.createElement('script') script.src = src document.head.append(script)}fu

正则y修饰符const s = 'aaa_aa_a'const r1 = /a+/g // ^ $const r2 = /a+/y // 粘连紧跟着查找console.log(r1.exec(s)) // aaaconsole.log(r2.exec(s)) // aaaconsole.log(r1.exec(s)) // aaaconsole.log(r2.exec(s)) // aaau修饰符编码let s2 = '\uD842\uDFB7'console.log(/^\u

字符连接/变量输出const a = 20const b = 10const c = 'javascript'// const str = 'my age is ' + (a + b) + ' i love ' + cconst str = `my age is ${a + b} i love ${c}`console.log(str)换行let g = `我是第一行换行了`console.log(g) /*我是第一行换行了*/字符串-函数function Price

Object文章目录Object基本使用拷贝基本使用属性值支持表达式和变量（要加[]）定义函数es5hello: function () { console.log('hello')}es6hello () { console.log('hello')}es5不支持异步方法定义变量属性es5let x = 1; let y = 2; let z = 3let obj = { x, y}obj[z + y] = 6es6let x = 1

函数默认值function f (x, y, z) { if (y === undefined) { y = 7 } if (z === undefined) { z = 42 } return x + y + z}console.log(f(3))es6function f6 (x, y = 7, z = 42) { return x + y + z} console.log(f6(1, undefined, 43))function

类Class文章目录类Class声明类读写属性的保护静态方法和类方法继承声明类创建类let Animal = function (type) { this.type = type this.eat = function () { console.log('I am eat food') }}let dog = new Animal('dog')let monkey = new Animal('Monkey')如果eat方法是静态方法在初始化时会发生占用大量空间，所以我们将

数组文章目录数组遍历一般方法each方法every方法for infor of(ES6)伪数组创建数组查找数组遍历一般方法const arr = [1,2,3,4,5]for (let i = 0; i < arr.length; i++) { const element = arr[i]; if(element===2){ // break continue } console.log(element)}each方法不

作用域文章目录作用域全局变量函数定义块状作用域（ES6新特性）var，const参考文献全局变量不应该在函数中var定义的，可以在整个项目中使用的var abc = 1234 //全局变量abcd = 2345 //全局(即windows)属性结果> abcd< 1453> delete window.abcd< true> delete window.abc< false> abcd VM608:1 Uncaught Refer