JavaScript Classes

🔹 What is a Class in JavaScript?

A class in JavaScript is a template for creating objects. It allows us to define properties (variables) and methods (functions) inside a structured format.

JavaScript classes were introduced in ES6 and provide a cleaner way to create and manage objects compared to traditional constructor functions.

🔹 Syntax of a JavaScript Class

class ClassName {
    constructor() {
        // Initialize properties
    }
    
    methodName() {
        // Define a method
    }
}

🔹 Example 1: Creating a Class and an Object

class Person {
    constructor(name, age) {
        this.name = name; // Property
        this.age = age;
    }

    greet() {  // Method
        console.log(`Hello, my name is ${this.name} and I am ${this.age} years old.`);
    }
}

// Creating an object
let person1 = new Person("John", 25);
person1.greet();

📌 Output: "Hello, my name is John and I am 25 years old."

The Person class defines a constructor to initialize properties.
The greet method prints a message.
person1 is an object created from the Person class.

🔹 Example 2: Class with Multiple Methods

class Car {
    constructor(brand, model) {
        this.brand = brand;
        this.model = model;
    }

    start() {
        console.log(`${this.brand} ${this.model} is starting...`);
    }

    stop() {
        console.log(`${this.brand} ${this.model} is stopping.`);
    }
}

// Creating an object
let myCar = new Car("Toyota", "Corolla");
myCar.start();
myCar.stop();

📌 Output:

Toyota Corolla is starting...
Toyota Corolla is stopping.

The Car class has two methods: start() and stop().
We create an instance myCar and call its methods.

🔹 Example 3: Class Inheritance (Extending a Class)

We can extend a class to create a child class.

class Animal {
    constructor(name) {
        this.name = name;
    }

    makeSound() {
        console.log(`${this.name} makes a sound.`);
    }
}

class Dog extends Animal {
    bark() {
        console.log(`${this.name} barks.`);
    }
}

let myDog = new Dog("Buddy");
myDog.makeSound(); // Inherited method
myDog.bark(); // Child class method

📌 Output:

Buddy makes a sound.
Buddy barks.

The Dog class inherits from Animal.
It can access both makeSound() and bark() methods.

🔹 Key Features of JavaScript Classes

✔ Encapsulation: Keeps data and functions together.
✔ Reusability: Easily create multiple objects from a single class.
✔ Inheritance: Allows child classes to inherit properties and methods.
✔ Better Readability: Cleaner structure compared to traditional functions.

🔹 Conclusion

Classes help organize and manage object creation in JavaScript.
They use a constructor to initialize properties.
Methods define the behavior of the class.
Inheritance allows extending a class for reusability.

JAVASCRIPT