javascript es6 编程风格

// 字符串:// 使用单引号''和反引号``, 避免使用双引号""// 反引号用${}插值let a: string = 'foobar';let b: string = `foo${a}bar`;console.log(b);

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// 数组解构; let arr: Array<number> = [1, 2, 3, 4];let [first, second] = arr;console.log(1, first, second)////////////////////////////////////////////////////// 对象解构: interface User {    firstName: string,    lastName: string}function getUserName(user: User): User {    let {firstName, lastName} = user;    // 当函数需要返回多个值的时候, 尽量使用对象形式的返回, 便于以后修改返回值的顺序以及添加新的返回内容    return {firstName, lastName};}console.log(2, getUserName({firstName: 'james', lastName: 'hellen'}));

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// 单行对象声明最后一项不加逗号, // 多行对象声明最后一行加逗号let a: any = {    k1: 1,    k2: 2,    k3: 3,}let b: any = {k1: 1, k2: 2, k3: 3};////////////////////////////////////////////////////function getKey(): string {    console.log('get key out');    return 'key' + 9;}let id: number = 1;// 对象属性名可以动态生成// 对象属性和接受变量的名称一致时可以简写let obj: any = {    id,    name: 'Shanghai',    [getKey()]: true};console.log(3, obj);let obj1: any = {    id,    value: id,    getKey(key: string) {        return key;    },    [getKey()]() {        console.log('get key in');    }};console.log(4, obj1);

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// 扩展运算符...// 数组拷贝let arr1: number[] = [1, 2, 3, 4];let arrCopy: number[] = [...arr1];console.log(5, arrCopy == arr1);

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// 箭头函数let arr2: number[] = [1, 2, 3, 4];arr2.sort((a, b) => Math.random() - 0.5);console.log(6, arr2);