JavaScript Next

Web Programming Course

SUT • Fall 2018

ES 2015+

let, const vs var
Arrow Functions
for…of
Default parameters
Spread, rest operator
Template literals
Enhanced object literal
Deconstructing

What's New

ES 2015+

let, const

let a = 50;
const b = 100;
if (true) {
  let a = 60;
  var c = 10;
  console.log(a/c); // 6
  console.log(b/c); // 10
}
console.log(c); // 10
console.log(a); // 50
b = 50 // TypeError: Assignment to constant variable.

Arrow Functions & Template Literals

const greetings = name => `hello ${name}`;

Examples

ES 2015+

import http from './http';

export default class User {
  constructor({ name, id }) {
    this.data = {
      name,
      id,
      info: {}
    }
    
    this.getUserInfo(id)
  }
  
  getUserInfo(id = 0) {
    return http.get(`/api/users/${id}`)
      .then(data => data.json())
      .then(data => {
        this.data.info = data;
      })
      .catch(() => {})
  }
}