---
id: 587d7dad367417b2b2512b78
title: Use a Constructor to Create Objects
challengeType: 1
---
## Description
Here's the Bird constructor from the previous challenge:
function Bird() {
this.name = "Albert";
this.color = "blue";
this.numLegs = 2;
// "this" inside the constructor always refers to the object being created
}
let blueBird = new Bird();
Notice that the new operator is used when calling a constructor. This tells JavaScript to create a new instance of Bird called blueBird. Without the new operator, this inside the constructor would not point to the newly created object, giving unexpected results.
Now blueBird has all the properties defined inside the Bird constructor:
blueBird.name; // => Albert
blueBird.color; // => blue
blueBird.numLegs; // => 2
Just like any other object, its properties can be accessed and modified:
blueBird.name = 'Elvira';
blueBird.name; // => Elvira
## Instructions
Use the Dog constructor from the last lesson to create a new instance of Dog, assigning it to a variable hound.
## Tests
```yml
tests:
- text: hound should be created using the Dog constructor.
testString: 'assert(hound instanceof Dog, ''hound should be created using the Dog constructor.'');'
- text: Your code should use the new operator to create an instance of Dog.
testString: 'assert(code.match(/new/g), ''Your code should use the new operator to create an instance of Dog.'');'
```
## Challenge Seed
```js
function Dog() {
this.name = "Rupert";
this.color = "brown";
this.numLegs = 4;
}
// Add your code below this line
```
## Solution
```js
function Dog() {
this.name = "Rupert";
this.color = "brown";
this.numLegs = 4;
}
const hound = new Dog();
```