Note the use of export/import and class inheritance in ES6

Just remember , I don't know if I have misunderstood

• export default This default export , import You can import the name directly , Don't add... To the name {}

• export Followed by a specific name ( Like the function name , Object name ), import When it comes to import Add braces {}

• es6 Classes of also have inheritance extends Grammatical sugar , To call a parent class method super.xxx(), Call the parent class to build super()

Here is an example , a.js Is the code in the parent class ：

class ParentClass{
    
    sayHello(){
    
        console.log("parent hello")
    }
}
class ParentClass2 extends ParentClass{
    
    sayHello(){
    
        console.log("parent2 hello")
        super.sayHello() // Calls a method of the parent class 
    }
}
export default{
    
    ParentClass2,
    name: 'ExpParentClass'
}
export const ParentClass3={
    
        sayHello(){
    
            console.log("ParentClass3 Const hello")
        }   
}

b.js quote a.js:

import {
    ParentClass3} from './a.js'
import ExpParentClass from './a.js'

class Son extends ExpParentClass.ParentClass2{
    
    sayHello(){
    
        console.log("-------------------")        
        super.sayHello()
        console.log("Son hello")
        console.log("-------------------")        
    }
}

let p1=new ExpParentClass.ParentClass2()
p1.sayHello()

let son=new Son()
son.sayHello()


ParentClass3.sayHello()

This directory should have a name package.json, adopt npm init -y Command line generation , type To set up for module

{
    
  "name": "study1",
  "version": "1.0.0",
  "description": "",
  "type": "module",
  "main": "index.js",
  "scripts": {
    
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC"
}