# Day 5: Inheritance Solution

Hello Friends in this article i am gone to share Hackerrank 10 days of javascript solutions with you. | Day 5: Inheritance Solution.

Also visit this link:  Day 4: Classes Solution

## Day 5: Inheritance Solution

### Objective

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 {
constructor(w){
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);

console.log(rec.area());
console.log(sqr.area());
} else {
console.log(-1);
console.log(-1);
}```

Complete the function in the editor. It has two parameters: a and b. It must return an object modeling a rectangle that has the following properties: Complete the function in the editor. It has two parameters: a and b. It must return an object modeling a rectangle that has the following properties: