JavaScript Classes

Blueprint for Objects:

• Classes in JavaScript provide a blueprint for creating objects with predefined properties and methods.

Constructor Method:

• Classes include a special method called the constructor, which is executed when a new instance of the class is created.

Encapsulation:

• Encapsulation allows bundling data (properties) and functionality (methods) within a single unit.

Example: Basic Class Declaration

class Rectangle {
  constructor(width, height) {
    this.width = width;
    this.height = height;
  }

  calculateArea() {
    return this.width * this.height;
  }
}

const rect = new Rectangle(5, 10);
console.log(rect.calculateArea()); // Output: 50

Inheritance:

• Classes support inheritance, allowing a child class (subclass) to inherit properties and methods from a parent class (superclass).

Example: Inheritance

class Square extends Rectangle {
  constructor(side) {
    super(side, side); // Calls the parent class constructor
  }
}

const square = new Square(5);
console.log(square.calculateArea()); // Output: 25

Static Methods:

• Static methods are associated with the class itself rather than instances of the class.

Example: Static Method

class MathUtils {
  static add(x, y) {
    return x + y;
  }
}

console.log(MathUtils.add(3, 5)); // Output: 8

 

Key Points

• JavaScript classes provide a modern syntax for creating objects and defining their behavior.
• They support encapsulation, inheritance, and static methods, enabling the creation of more structured and reusable code.
• Classes enhance code organization and readability, making it easier to work with complex data structures and object-oriented patterns.