Example of classes in JavaScript ES2015

classes.js

class Person {
  constructor(name = 'Anonymous', age = 0) {
    this.name = name
    this.age = age
  }
  getGreeting(){
    return `Hi, I am ${this.name}`
  }
  getDescription(){
    return `${this.name} is ${this.age} years old`
  }

} // class Person

class Student extends Person {
  constructor(name, age, major) {
    super(name, age)
    this.major = major
  }
  hasMajor() {
    return !!this.major
  }
  getDescription(){
    let description = super.getDescription()
    // from this line, description will already by having the returned string
    // using 'this' name & age from the super Class constructor

    if (this.hasMajor()) {
      description += ` Their major is ${this.major}`
    }
    return description
  }
} // class Student

class Traveler extends Person {
  constructor(name, age, homeLocation) {
    super(name, age)
    this.homeLocation = homeLocation
  }

  hasHomeLocation() {
    return !!this.homeLocation
  }
  getGreeting(){
    let description = super.getGreeting()

    if (this.hasHomeLocation()) {
      description += ` My homeLocation is ${this.homeLocation}`
    }
    return description
  }

} // class Traveler


const me = new Student('Hani Y', 50, 'Computer Science')
console.log(me.getDescription());

const other = new Student()
console.log(other.getDescription());

const traveler = new Traveler('Hani Traveler', 35, 'Jeddah')
console.log(traveler.getGreeting());