class2.js

class Developer extends Person {
    constructor (firstName, lastName, role) {
        super(firstName, lastName);
        this.role = role;
    }

    hello () {
        console.log(`My name is ${this.firstName} ${this.lastName} and I am a ${this.role}`);
    }
    
    static haha () {
        console.log('haha');
    }
}

let hckrmoon = new Developer('Jooyoung', 'Moon', 'Web Developer');
hckrmoon.hello(); // My name is Jooyoung Moon and I am a Web Developer