let myKey = 'key3';
let obj = {
  key1: 'One',
  key2: 'Two'
};
obj[myKey] = 'Three';

let myKey = 'variableKey';
let obj = {
  key1: 'One',
  key2: 'Two',
  [myKey]: 'Three' /* yay! */
};

// Adds a 10% tax to total
let calculateTotal = total => total * 1.1;
calculateTotal(10) // 11

// Cancel an event -- another tiny task
let brickEvent = e => e.preventDefault();
document.querySelector('div').addEventListener('click', brickEvent);

let age = [12,19,6,4];

let firstAdult = ages.find(age => age >= 18); // 19
let firstAdultIndex = ages.findIndex(age => age >= 19); // 1

// Pass to function that expects separate multiple arguments
// Much like Function.prototype.apply() does
let numbers = [9, 4, 7, 1];
Math.min(...numbers); // 1

// Convert NodeList to Array
let divsArray = [...document.querySelectorAll('div')];

// Convert Arguments to Array
let argsArray = [...arguments];

// Multiline String
let myString = `Hello

I'm a new line`;

//Basic interpolations
let obj = {x:1,y:2};

console.log(`Your total is: ${obj.x + obj.y}`); // Your total is 3

//Basic usage

function great( name = 'Anon' ){
  console.log(`Hello ${name}`);
}

great(); // Hello Anon!

//You can have a function too!

function greet( name = 'Anon',callback = function(){} ){
  console.log(`Hello ${name}!`);
  // No more "callback && callback()" (no conditional)
  callback();
}

// Only set a default for one parameter
function greet(name, callback = function(){}) {}