简评:ES6(ECMAScript2015)实际上是一种新的 JavaScript 规范,包含了一些很棒的新特性,可以更加方便地实现很多复杂的操作。
先看一下 ES6 的新特性:
- Default Parameters in ES6(默认参数)
- Template Literals in ES6(模板文本)
- Multi-line Strings in ES6(多行字符串)
- Destructuring Assignment in ES6(解构赋值)
- Enhanced Object Literals in ES6(增强的对象文本)
- Arrow Functions in ES6(箭头函数)
- Promises in ES6
- Block-Scoped Constructs Let and Const(块作用域构造 Let and Const)
- Classes in ES6(类)
- Modules in ES6(模块)
Hack #1: Swap variables 交换变量
使用 Array Destructuring 交换值
let a = 'world', b = 'hello'
[a, b] = [b, a]
console.log(a) // -> hello
console.log(b) // -> world
// Yes, it's magic
Hack #2 : Async/Await with Destructuring
下面这段代码可以同时发起两个异步请求,把请求结果分别附到 user 和 account 中
const [user, account] = await Promise.all([
fetch('/user'),
fetch('/account')
])
Hack #3 : Debugging
const a = 5, b = 6, c = 7
console.log({ a, b, c })
// outputs this nice object:
// {
// a: 5,
// b: 6,
// c: 7
// }
Hack #4 : One liners
更紧凑的数组操作语法
// Find max value
const max = (arr) => Math.max(...arr);
max([123, 321, 32]) // outputs: 321
// Sum array
const sum = (arr) => arr.reduce((a, b) => (a + b), 0)
sum([1, 2, 3, 4]) // output: 10
Hack #5 : Array concatenation
展开运算符可以用来代替 concat
const one = ['a', 'b', 'c']
const two = ['d', 'e', 'f']
const three = ['g', 'h', 'i']
// Old way #1
const result = one.concat(two, three)
// Old way #2
const result = [].concat(one, two, three)
// New
const result = [...one, ...two, ...three]
Hack #6 : Cloning
const obj = { ...oldObj }
const arr = [ ...oldArr ]
Hack #7 : Named parameters 参数命名
const getStuffNotBad = (id, force, verbose) => {
...do stuff
}
const getStuffAwesome = ({ id, name, force, verbose }) => {
...do stuff
}
// Somewhere else in the codebase... WTF is true, true?
getStuffNotBad(150, true, true)
// Somewhere else in the codebase... I ❤ JS!!!
getStuffAwesome({ id: 150, force: true, verbose: true })
原文链接:7 Hacks for ES6 Developers
推荐阅读:Level UP! 提升你的编程技能
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