JS常用方法

#查询某元素
document.querySelectorAll("div.aa")

#数组属性赋值
let [a, b, c] = [1, 2, 3]

#对象属性赋值
let jsonData = {
id: 42,
status: "OK",
data: [867, 5309]
}
let { id, status, data: number } = jsonData

#数组转对象
let domainList =[1,2,3]
let allListDomain = domainList.map(item => {return { label: item, value: item }})

#查找数组某个对象的位置
let CGOptions = [{name:'1'}]
let findIndex = CGOptions.findIndex(item => item.name === '2')

#对象合并
let target = { a: 1, b: 2 };
let source = { b: 4, c: 5 };
let returnedTarget = Object.assign(target, source)

#获取对象的某几个元素组成新的对象
let obj = {name:'test',time:'2021-08-10',num:'1'}
let arr = ['name','time']
let PickObjValue = (obj, arr) => arr.reduce((iter, val) => (val in obj && (iter[val] = obj[val]), iter), {})
let newobj = PickObjValue(obj,arr)
#获取对象的某几个元素组成新的对象
let obj = {name:'test',time:'2021-08-10',num:'1'}
let {name,...newobj} = obj //删除属性name

#数组去重
let newArray =[1,2,3,4,2]
let array = [...new Set(newArray)] //去重

#对象中的扩展运算符(...)
let bar = { a: 1, b: 2 };
let baz = { ...bar }; // { a: 1, b: 2 }

#filter过滤
var arr = [1,5,2,'10',6];
var arr1= arr.filter(item=>{
if(item>2){
return item+1;
}
})
const [first, ...rest] = [1, 2, 3, 4, 5]; //first 1 rest [2, 3, 4, 5]