Extending Prototypes in JavaScript: Adding Custom Properties & Methods

Effortlessly enhance existing constructors with unique features tailored to your needs

Photo by Tim Arterbury on Unsplash

When working with JavaScript, one powerful feature is the ability to modify built-in prototypes or even create custom ones. Extending prototypes enables you to add new functionality to existing constructors — like Array, String, or Date — or build entirely new ones suited to your project requirements.

This tutorial covers adding custom properties and methods to native and user-defined prototypes, providing practical examples along the way. Let’s dive right in!

Adding Properties and Methods to Native Constructors

Native constructors already have default functionalities, but sometimes, they lack certain capabilities necessary for particular tasks. To address this issue, you may augment their prototypes with additional methods or properties. Here’s how to achieve this:

1. Access the desired constructor’s prototype.
2. Create a new property or method within the prototype object.
3. Assign values to the newly created property or method.