Subclassing
So far, we discussed how to declare classes and the types of members classes can support. A major use of a class is to serve as a template to create other subclasses. When you create a child class from a class, you derive properties of the parent class and extend the parent class by adding more features of its own.
Let's look at the following de facto example of inheritance:
class Animal {
constructor(name) {
this.name = name;
}
speak() {
console.log(this.name + ' generic noise');
}
}
class Cat extends Animal {
speak() {
console.log(this.name + ' says Meow.');
}
}
var c = new Cat('Grace');
c.speak();//"Grace says Meow."
Here, Animal is the base class and the Cat class is derived from the class Animal. The extend clause allows you to create a subclass of an existing class. This example demonstrates the syntax...
