ES7特性

ES7

• 没有this
• 箭头函数
  对比
  ES6

class Human{
  this.gender = ‘male’
  printGender(){
    console.log(this.gender);
  }
}
class Person extends Human{
  constructor(){
    super();
    this.name='max'
    this.gender = 'female'
    
  }
  printMyName(){
    console.log(this.name);
    
  }
  
}

ES7

class Human{
  gender = ‘male’
  printGender=()=>console.log(this.gender);
  
}
class Person extends Human{
  
  name='max'
  gender = 'female'

  printMyName=()=> console.log(this.name);
  
}

Spread & Rest Operator

spread ...
split up arr or obj properties

const newArr = [...oldArr,1,2]
const newObj = {...oldObj,newP:5}

rest ...
merge a list of dunction arguments into an arr

function sortArr(...arg){
  return args.sort()
}
const filter = (...args)=>return args.filter(e=>e===1);

Destructuring

Array destructuring

const n=[1,2,3]
[n1,,n3]=n;//=>n1=1,n3=3

Object destructuring

ob={name:'a',age:22}
{name}=ob

Reference & primitive types refresher 浅拷贝

参考ES6

Reference function

function 不是浅拷贝
object和arr是浅拷贝

import arr functions

1.map()
2.filter()
3.reduce()
4.find()
5.findIndex()
6.concat() 衔接
7.slice() 拆分
8.splice() 插入