Classes

Classes in TypeScript are a foundational concept from object-oriented programming (OOP). They provide a blueprint for creating objects, encompassing both the data attributes and the methods to manipulate this data.

Defining a Class

In TypeScript, a class is created using the class keyword. Classes may contain:

Fields: These are variables within the class that store data.

name: string;

Constructor: This is a special method used to initialize a new instance of the class.

 constructor(name: string) {
     this.name = name;
 }

Methods: Functions defined within the class to perform specific tasks.

speak(): void {
    console.log(`${this.name} makes a noise.`);
}

Inheritance

TypeScript supports inheritance, allowing a new class (known as a subclass) to derive from an existing class (superclass). The extends keyword facilitates this.

When a subclass extends a superclass, it inherits all properties and methods. However, it can also:

1. Add new properties or methods.
2. Override existing methods.

Example:

class Animal {
    name: string;

    constructor(name: string) {
        this.name = name;
    }

    speak(): void {
        console.log(`${this.name} makes a noise.`);
    }
}

Exercise

Using the inheritance concept in TypeScript, you're tasked to extend the Animal class to craft a Dog class. Ensure the Dog class overrides the speak method so it prints ${name} barks when called.