es6-classes-1.js

class Person {
    constructor(name) {
        this.name = name;
    }
}

class GreatPerson extends Person {
    constructor(name, phrase) {
        super(name);
        this.phrase = phrase;
    }
}

class FuckingGreatPerson extends GreatPerson {
    constructor(name, phrase) {
        super(name, phrase);
        this.say();
    }
    say () {
        alert(this.name + ' says ' + this.phrase);
    }
}

let kek = new FuckingGreatPerson('kek', 'lol');