ES6 presentation

es.js

function myFnc() {
  if (true) {
    let a = 'oi';
    console.log(a + ' gdg'); // oi gdg
  }
  
  console.log(a); // a is not defined
}

// myFnc();

const num = 1;
//num = 2; // "num" is read-only

const ary = [];
ary.push(1);
console.log(ary); // [1]

class Human {
  constructor(name) {
    this.name = name;
  }
  
  describe() {
    return 'Human name is ' + this.name;
  }
}
let h = new Human('Luiz');
console.log(h.describe()); // Human name is Luiz

class Developer extends Human {
  constructor(name, favoriteLanguage) {
    super(name);
    this.favoriteLanguage = favoriteLanguage;
  }
  
  describe() {
    return `${super.describe()} and its favorite language is ${this.favoriteLanguage}`;
  }
}
let d = new Developer('Luiz', 'JavaScript'); // Human name is Luiz and its favorite language is JavaScript
console.log(d.describe());

let [a, , b] = [1, 2, 3];
console.log(`${a}, ${b}`); // 1, 3

let { first, last } = { first: 'Jane', last: 'Doe' };
console.log(`${first}, ${last}`); //Jane, Doe