JEST简介

中文简介
官方
DOM testing lib

ES2018简介

中括号
const numbers = [1, 2, 3, 4, 5]
[first, second, ...others] = numbers

小括号
const numbers = [1, 2, 3, 4, 5]
const sum = (a, b, c, d, e) => a + b + c + d + e
const sumOfNumbers = sum(...numbers)

大括号
const { first, second, ...others } = { first: 1, second: 2, third: 3, fourth: 4, fifth: 5 }

first // 1
second // 2
others // { third: 3, fourth: 4, fifth: 5 }

const items = { first, second, ...others }
items //{ first: 1, second: 2, third: 3, fourth: 4, fifth: 5 }

some：
return the first one-> true/false without going through all elements
[2, 5, 8, 1, 4].some(isBiggerThan10);

map:
let r = res.map(item => {
    return {
        title: item.name,
        sex: item.sex === 1? '男':item.sex === 0?'女':'保密',
        age: item.age,
        avatar: item.img
    }
})

filter:
var marvelHeroes =  heroes.filter(function(hero) {
    return hero.franchise == “Marvel”;
});
           

ES2018