Day 5: Inheritance | 10 Days Of JavaScript | HackerRank Solution

Hello coders, today we are going to solve Day 5: Inheritance HackerRank Solution which is a part of 10 Days of JavaScript Series.

Day 5: Inheritance


In this challenge, we practice implementing inheritance and use JavaScript prototypes to add a new method to an existing prototype.


We provide the implementation for a Rectangle class in the editor. Perform the following tasks:

  1. Add an area method to Rectangle‘s prototype.
  2. Create a Square class that satisfies the following:
    • It is a subclass of Rectangle.
    • It contains a constructor and no other methods.
    • It can use the Rectangle class’ area method to print the area of a Square object.

Locked code in the editor tests the class and method implementations and prints the area values to STDOUT.

Solution – Day 5: Inheritance

class Rectangle {
    constructor(w, h) {
        this.w = w;
        this.h = h;

 *  Write code that adds an 'area' method to the Rectangle class' prototype
 Rectangle.prototype.area = function() {
     return (this.w * this.h);
 class Square extends Rectangle {
         super(w, w);
 * Create a Square class that inherits from Rectangle and implement its class constructor

if (JSON.stringify(Object.getOwnPropertyNames(Square.prototype)) === JSON.stringify([ 'constructor' ])) {
    const rec = new Rectangle(3, 4);
    const sqr = new Square(3);
} else {

Disclaimer: The above Problem (Inheritance) is generated by Hacker Rank but the Solution is provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.

Leave a Comment

Your email address will not be published. Required fields are marked *