Extending a class

Extending classes can be used to allow for new behaviors, while adhering to common interfaces. While it's not always the best way to organize relationships between objects, there are many situations where extension (sometimes called inheritance) is the most effective way to structure behavior.

In this recipe, we'll see a very simple example of extension.

Getting ready

This recipe assumes you already have a workspace that allows you to create and run ES modules in your browser. If you don't, please see the first two chapters.

How to do it...

1. Open your command-line application and navigate to your workspace.
2. Create a new folder named 08-01-extending-classes.
3. Copy or create an index.html that loads and runs a main function from main.js.
4. Create a main.js file that defines a new class named Rocket that takes a constructor argument name and assigns it to an instance property:

// main.js 
class Rocket { 
  constructor(name) { 
    this.name = name; 
  } 
} 

5. Create a class named InactiveRocket...