Arrow function demo 1 (console): Iterate over an array
var bob = {
    _name: "Bob",
    _friends: ["Jack","Sue","Barney"],  // ADDED NAMES
    printFriends() {
        this._friends.forEach(f =>
            console.log(this._name + " knows " + f));
    }
}
console.log("Arrow function demo 1");

Arrow function demo 2 (console): Increment to the console
function count() {
    var count = 0
    nIntervId = setInterval(() => console.log(count++), 400);
}

Template demo: Replace text
var name = "Bob", time = "today", nIntervId;
var tmptxt = document.getElementById('temp1');

tmptxt.insertAdjacentHTML('beforeend',`Hello ${name}, how are you ${time}?`);


More detail: ES6 In Depth: Template strings
Promise demo: Asynchronous programming