实用的js操作

记录下本人在学习过程中觉得比较好的小例子，整理成笔记，便于后来查看

• 判断数据类型

//判断对象的数据类型
const isType = type =>target =>`[object ${type}]`===Object.prototype.toString.call(target);
const isArray=isType("Array");
console.log(isArray([]))

• 数组去重

const arr = [1,2,2,2,6,6,6,5];
//method one
console.log(Array.from(new Set(arr))) //[1,2,6,5]
//method two
console.log([...new Set(arr)])   //[1,2,6,5]

• 对象合并，...扩展运算符

let obj1 = {name:"san zhang",age:15};
let obj2 = {name:"san zhang",sex:"male",like:"basketball"};
let newobj = {...obj1,...obj2};
console.log(newobj);   //{name: "san zhang", age: 15, sex: "male", like: "basketball"}

• 数组的遍历方法（not Array.Map）

let users =[{name:"Jack",age:15},{name:"Rose",age:18},{name:"Tom",age:16}];
console.log(Array.from(users,{name}=>name));  //["Jack", "Rose", "Tom"]
//equal map
console.log(users.map(user=>user.name))

• ...运算符 and 解构赋值

let userInfo ={
  name:"老学长",
  age:15,
  classroom:"15-1",
  birthday:"10.5",
  sex:"male"
}
let baseInfo={},user ={};
({name:baseInfo.name,sex:baseInfo.sex,...user} = userInfo);
console.log(baseInfo);  //{name: "老学长", sex: "male"}
console.log(user);  //{age: 15, classroom: "15-1", birthday: "10.5"}

• 属性名动态赋值

let key = "name";
let obj = {
  [key]:"big brother"
}
console.log(obj)  //{name: "big brother"}