Inheritance in ES6

 First let see the example of how inheritance works in ES5.

var Person5 = function (name, yearOfBirth, job) {

    this.name = name;

    this.yearofBirth = yearOfBirth;

    this.job = job;

}

Person5.prototype.calculateAge = function() {

    var age = new Date().getFullYear() - this.yearOfBirth;

    console.log(age);

}

var Athlete5 = function(name, yearOfBirth, job, olympicGames, medals) {

    Person5.call(this, name, yearOfBirth, job);

    this.olympicGames = olympicGames;

    this.medals = medals;

}

Athlete5.prototype = Object.create(Person5.prototype); //will create new instance and point prototype of Person5                                                                                           to Athlete5. So that now we can access the prototype of                                                                                             Person5 using object of Athlete5.

var johnAthlete5 = new Athlete5('lokman', 1990, 'engineer', 'swimmer', 3);

johnAthlete5.calculateAge();

Here ,Athlete5 is inheriting Person5. 

//ES6

class Person6 {

    constructor(name, yearOfBirth, job) {

        this.name = name;

        this.yearofBirth = yearOfBirth;

        this.job = job;

    }

    calculateAge() {

        var age = new Date().getFullYear() - this.yearofBirth;

        console.log(age);

    }

}

class Athlete6 extends Person6 {

    constructor(name, yearOfBirth, job, olympicGames, medal) {

        super(name, yearOfBirth, job);

        this.olympicGames = olympicGames;

        this.medals = medal;

    }

    

    wonmedals(){

        this.wonmedals++;

        console.log(this.medals);

    }

}

const johnatlete6 = new Athlete6("john",1989,"engineer","tokyo",1);

johnatlete6.calculateAge();

johnatlete6.wonmedals();