Class declartion and inheritance in Javascript ES6

es6classes.js

// a simple class declaration in es6
class Person {
  constructor(fname, lname) {
  	this.fname = fname;
    this.lname = lname;
  }
  
  toString() {
  	return (this.fname + " " + this.lname);  
  }
}

// this class extends the Person
class Employee extends Person {
  constructor(fname, lname, position) {
  	super(fname, lname);
    this.position = position;
  }
  
  toString() {
    return (this.fname + " " + this.lname + " is a " + this.position);  
  }
}

// instantiate and run a class method
var person = new Person("John", "Smith");
console.log(person.toString());

// instantiate the child class
var employee = new Employee("John", "Matrix", "Commando");
console.log(employee.toString());