属性简写
let a = 1;
let obj = { a }
console.log(obj) //{a:1}可计算的属性值
let count = 0function addcount(key) {return `${key}_${count++}`}const nameKey = 'name';const agekey = "age";const jobKey = "job";let person = {[addcount(nameKey)]: 'Matt',[addcount(agekey)]: 27,[addcount(jobKey)]: '小明'}console.log(person) //{name_0:'Matt',age_1,27,job_2:'小明'}console.log(nameKey) //name、简写的方法名
let obj2 = {// sayName: function (name) {// console.log(name)// }// 简写sayName(name) {console.log(name)}}obj2.sayName('执行了')解构赋值
可以设置默认值,对象中属性值为undefined或为空时，默认值生效
【注意】：直接解构null或undefined会抛出错误
数组解构赋值
let [a,b]=[1,2]
//交换两个变量的值
let[a,b]=[b,a]
//扩展运算符的运用
let[a,...b]=[1,2,3]
//有默认值 右侧的参数等于undefined，默认值生效
let[a=3,b]=[1,2]对象解构赋值
let {a,b}={a:1,b:2}
//等价于
let {a:a,b:b}={a:1,b:2};let{a,...b}={a:1,b:2,c:3}嵌套解构
可以通过嵌套解构复制对象数组
let person = {name: '小红',age: 12,say: {talk: '脱口秀'}};let personCopy = {};({ name: personCopy.name, age: personCopy.age, say: personCopy.say } = person)console.log(personCopy)let { say: { talk } } = person;console.log(talk) // "脱口秀"参考上下文匹配
//在参数列表中进行解构赋值let person = {name: '小红',age: 12};function woman(color, { name, age }, sex) {//对参数解构赋值不会影响arguments对象console.log(arguments)console.log(name, age)}woman('red', person, '女')
