ES6 Examples

arrow_functions_no_arg.js

var getNum = () => 5;

// Translates to 
var getNum = function(){
  return 5;
}

arrow_functions_one_arg.js

var modByTwo = val => val % 2;

// Translates to 
var modByTwo = function(val){
  return val % 2;
}

arrow_functions_return.js

var add =  (val1, val2) => val1 + val2;

// Translates to
var add = function(val1, val2){
  return val1 + val2;
}

block_scope_example.js

let cipherhack = 100;
if (cipherhack > 0) {
  let cipherhack = 10;
}
console.log(cipherhack);
// OUTPUT: 100

const cipherhack2 = 100;
if (cipherhack2 > 0){
  const cipherhack2 = 2;
}
console.log(cipherhack2);
// OUTPUT 100

const_example.js

'use strict'
const CONTROL_GROUP;
// Uncaught SyntaxError: Missing initializer in const declaration

const CONTROL_GROUP = 10;
CONTROL_GROUP = 100;
console.log(CONTROL_GROUP);
// Uncaught TypeError: Assignment to constant variable.

default_examples.js

var greetUser = function(greeting = "Hi", userName = "user"){
  console.log(greeting + "! " + userName + '.');
}

greetUser(); // OUTPUT: Hi! user.
greetUser('Hello'); // OUTPUT: Hello! user.
greetUser(undefined, 'Cipherhack'); // OUTPUT: Hi! Cipherhack.
greetUser('Hello', 'Cipherhack'); // OUTPUT: Hello! Cipherhack.

default_exp_example.js

var addTax = function (price, tax = price * 0.2){
  console.log(price + tax);
}

addTax(100); // OUTPUT: 120
addTax(100, 30); // OUTPUT: 130

destructure.js

var arr = [100, 200, 300];
var [small, mid, large] = arr;
console.log(large)
// OUTPUT: 300

var [small, ...remaining] = arr;
console.log(remaining);
// OUTPUT [200, 300]

destructuring_object.js

var person = {firstname: 'Cipher', lastname:'Hack', address: 'Hello World'};
// variables should match with objects keys
let {firstname, lastname, address} = person
console.log(lastname);
// OUTPUT: "Hack"

// We can also rename the variables
let {firstname:fname, lastname:lname, address:add} = person
console.log(lname);
// OUTPUT: "Hack"

for_of_loop.js

var currencies = ['Bitcoin', 'Ether', 'Ripple'];
for (var carrency of currencies){
  console.log(carrency);
}
//OUTPUT: Bitcoin, Ether, Ripple

let_example.js

'use strict';
// using var, cipherhack will be hoisted
console.log(cipherhack);
var cipherhack = 1;
//OUTPUT: undefined

// using let, cipherhack2 will not be hoisted
console.log(cipherhack2);
let cipherhack2 = 2;
//OUTPUT: ReferenceError: cipherhack2 is not defined

//using let and assigning
let cipherhack3 = 3;
console.log(cipherhack3);
//OUTPUT: 3

//using let and not assigning
let cipherhack3;
console.log(cipherhack3);
//OUTPUT: undefined

object_literal.js

var firstname = 'Cipher';
var lastname = 'Hack';
var obj = {
  firstname,
  lastname
}

console.log(obj)
//OUPUT
{firstname: 'Cipher', lastname: 'Hack'}

object_literal_dynamic_keys.js

var dynamicKey = 'dKey';
var value = 'Cipherhack';
var obj = {
  [dynamicKey + '-01']:value
}
console.log(obj);
// OUPUT: {dKey-01: "Cipherhack"}

object_literal_functions.js

var firstname = 'Cipher';
var lastname = 'Hack';
var obj = {
  firstname,
  lastname,
  log(){
    console.log(this.firstname + " " + this.lastname);
  }
}

console.log(obj.log());
//OUPUT: Cipher Hack

octals_binary.js

'use strict'
var octal = 0o10;
console.log(octal); 
// OUTPUT: 8

var binary = 0b10;
console.log(binary); 
// OUTPUT: 2

promise_example.js

function asyncFn() {
    let prom = new Promise(function(resolve, reject){
        console.log('Entered in promise');
        setTimeout(function(){
            console.log('resolving promise');
            resolve('OK');
        },2000);
    });
    return prom;
}

asyncFn().then(function(data){
    console.log(data);
}, function(err) {
    console.log(err);
});
// OUTPUT"
// Entered in promise
// Promise {<pending>}
// resolving promise
// OK

rest_example.js

var getProduct = function (product, ...companies){
  console.log(companies);
  console.log(companies instanceOf Array);
}

getProducts('Mobile', "Apple", "Samsung")
// OUTPUT: ["Apple", "Samsung"]
// OUTPUT: true
getProducts('Mobile')
// OUTPUT: []
// OUTPUT: true

spread_example.js

var ages = [12,3,43,80];
var oldest = Math.max(...ages);
console.log(oldest);
// OUTPUT: 80

var chars = ["A", ..."BCD", "E"]
console.log(chars);
// OUTPUT: ["A","B","C","D","E"]

template_leterals.js

'use strict';
var productId = 123;
console.log(`Product ID: ${productId}`);
// OUTPUT: Product ID: 123

console.log(`Product ID: ${"APPLE-" + productId}`); // Expression
// OUTPUT: Product ID: 123
Product ID: APPLE-123