ES6 new features

http://es6-features.org/#Constants

ES6 New Features

• Let, Const

• Class

• Arrow Function

• Spread Operator and Destructing

• Modules

• Promise

• Symbol

• Typed Arrays

• Internationalization & Localization

Class

// ES6
class Human {
    constructor() {
        this.gender = "female";
    }
    
    printGender() {
        console.log(this.gender);
    }
}

class Person extends Human {
    constructor() {
        super();
        this.name = "Harry";
        this.gender = "male";
    }
    
    printMyName() {
        console.log(this.name);
    }
}

const person = new Person();
person.printMyName(); // "Harry"
person.printGender(); // "male"

// ES7
class Human {            
    gender = "female";           
    
    printGender = () => {        
        console.log(this.gender);    
    }
}

class Person extends Human {           
    name = "Harry";        
    gender = "male";         
    
    printMyName = () => {        
        console.log(this.name);    
    }
}
const person = new Person();
person.printMyName(); // "Harry"
person.printGender(); // "male"

Exports & Imports

Default export	Named export
You can choose the name when import	Name is defined by export
import person from "./person.js"	import {person as Person} from "./utility.js"
	import * as bundle from "./utility.js"

Spread & Rest Operators ...

Spread	Rest
Used to split up array elements OR object properties	Used to merge a list of function arguments into an array
const newObject = {...oldObject, newProp: 5};	function sortArgs(...) {return args.sort();}

Destructuring

Easily extract array elements or object properties and store them in variables

Array Destructuring	Object Destructuring
[a, b] = ["Hello", "Harry"];	{name} = {name: "Harry", gender: "male"};

Declaration

letDeclares a block-scoped, local variable, optionally initializing it to a value.

constDeclares a block-scoped, read-only named constant.

varDeclares a variable, optionally initializing it to a value.