ES6, ES7, ES8 Features

es678.js

// This is sourced from the video -> https://www.youtube.com/watch?v=nZ1DMMsyVyI&t=2s

// Template Literals
const firstName = 'John';
const lastName = 'Doe';

console.log(`Hello: ${firstName} ${lastName}`); // Hello: John Doe

// Object Destructuring
const person = {
  name: 'Jon',
  age: 30,
  house: 'Stark',
  strength: 'Leader'
};

let {name, age} = person;
console.log(`${name} is ${age} years old!`); // Jon is 30 years old

// Array Destructuring
let [stark, targareyan, lannister] = ['Jon', 'Dany', 'Tyrion', 'Arya'];

console.log(stark); // Jon
console.log(lannister); // Tyrion

stark = 'Ned'; // You can update the index of the array like this!
console.log(stark); // Ned

// Object Literals
function kingMaker(house, name) {
    const supporter = {house, name}; // You don't need to write the key part, by default, it is assigned to the same key name
    console.log(`${name} of house ${house} is a king maker!`);
}

kingMaker('Mormont', 'Lyanna');

// for-of loop
let prices = [20, 30, 40, 50, 60];
let total = 0;

for (const price of prices) {
    console.log(price);
    total += price;
}

console.log(total);

let kingdoms = "Starks";

// Iterable - Maps, sets, arrays etc.
for (const char of kingdoms) {
    console.log(char);
}

// Spread operator
let direwolves = ['Nymeria', 'Ghost'];
let wolves = [...direwolves];
wolves.push('Lady');

console.log(wolves);

let direwolvesObj = {
    name: 'Nymeria'
};

let wolvesObj = {
    ...direwolvesObj
};

console.log(wolvesObj);

// Rest operator
function battle(...kings) {
    console.log(kings);
}

battle('Jon', 'Ramsay');

// Arrow Functions
let nums = [1, 2, 3];
let sum = nums.reduce((x, y) => x + y);
console.log(sum);

// Default parameters
function add(numArray = []) {
    let total = 0;
    numArray.forEach((element) => {
        total += element;
    });

    console.log(total);
}

add();
add([1, 2, 3]);

// Includes function
let numbers = [1, 2, 3];
console.log(numbers.includes(2));
console.log(numbers.includes(5));

// Pad start and pad end methods
let example = 'Jon';
console.log(example.padStart(10, 'J'));
console.log(example.padEnd(5, 'n'));

// Classes
class Animal {

    constructor(type, legs) {
        this.type = type;
        this.legs = legs;
    }

    sayHello() {
        console.log(`Hi, I'm a ${this.type} and I have ${this.legs} legs`);
    }

    static sayHi() {
        console.log("Hello there!");
    }

    // getters
    get metaData() {
        return `Type: ${this.type}, Legs: ${this.legs}`;
    }

}

let cat = new Animal('cat', 4);
cat.sayHello();
console.log(cat.metaData); // metadata is now a property on our object

// static function
Animal.sayHi();

// Inheritance
class Mammal extends Animal {

    constructor(type, legs, vegetarian) {
        super(type, legs);
        this.vegetarian = vegetarian;
    }

    sayHello() {
        console.log(`Hi, I'm a ${this.type} and I have ${this.legs} legs. And, I'm a vegetarian? ${this.vegetarian}`);
    }

}

let mam = new Mammal('cow', 4, true);
mam.sayHello();
console.log(mam.metaData);

// Async and await
const apiUrl = 'https://jsonplaceholder.typicode.com/todos/1';

const fetch = require("node-fetch");
const getTodos = async () => {
    let res = await fetch(apiUrl);
    let json = await res.json();
    console.log(json);
};

getTodos();

// Sets
const exampleSet = new Set(['a', 'a', 'b', 'c', 'd', 'd']);
exampleSet.add('e');
exampleSet.add('a');
exampleSet.delete('c');

console.log(exampleSet);
console.log(exampleSet.has('a'));
console.log(exampleSet.has('c'));