JavaScript Classes

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Level : Intermediate

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Mentor: Shailendra Chauhan

Duration : 00:00:45

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Class:

Classes are templates for creating objects with shared properties and methods.

Example:

class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }
  greet() {
    console.log('Hello, my name is ${this.name}!');
  }
}
let person1 = new Person("Alice", 25);
person1.greet(); // Output: Hello, my name is Alice!

Class Constructor:

The constructor initializes object properties when an instance of a class is created.

Example:

class Rectangle {
  constructor(width, height) {
    this.width = width;
    this.height = height;
  }
}
let rect = new Rectangle(10, 5);
console.log(rect.width); // Output: 10

Class Methods:

Class methods are functions defined within a class, providing behavior to instances of the class.

Example:

class Circle {
  constructor(radius) {
    this.radius = radius;
  }
  calculateArea() {
    return Math.PI * this.radius  2;
  }
}
let circle1 = new Circle(3);
console.log(circle1.calculateArea()); // Output: 28.274333882308138

Static Methods:

Static methods belong to the class itself, not its instances, often used for utility functions.

Example:

class MathUtils {
  static multiply(a, b) {
    return a * b;
  }
}
console.log(MathUtils.multiply(5, 3)); // Output: 15

Extends:

The 'extends' keyword allows a child class to inherit properties and methods from a parent class.

Example:

class Animal {
  constructor(name) {
    this.name = name;
  }
  speak() {
    console.log('${this.name} makes a sound.');
  }
}
class Dog extends Animal {
  speak() {
    console.log('${this.name} barks.');
  }
}
let dog1 = new Dog("Buddy");
dog1.speak(); // Output: Buddy barks.

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