Why Use the Factory Pattern ?

• Centralized Object Creation : Keeps object creation in one place.
• Flexibility : Easily add new object types without modifying existing code.
• Code Reusability : Simplifies object creation logic across your application.

Factory Pattern in JavaScript :

// Factory function to create car objects
function CarFactory() {

  this.createCar = function (type) {
    let car;
    if (type === 'sedan') {
      car = new Sedan();
    } else if (type === 'suv') {
      car = new SUV();
    } else if (type === 'truck') {
      car = new Truck();
    }
    car.type = type;
    car.drive = function () {
      console.log(`Driving a ${this.type}`);
    };
  return car;
  };
}


// Car types (constructors)
function Sedan() {
  this.doors = 4;
}
function SUV() {
  this.doors = 4;
}
function Truck() {
  this.doors = 2;
}

// Usage
const factory = new CarFactory();
const mySedan = factory.createCar('sedan');
const mySUV = factory.createCar('suv');
mySedan.drive(); // Outputs: Driving a sedan
mySUV.drive();  // Outputs: Driving a suv

Key Benefits :

1. Centralized Creation : Encapsulates object creation logic in one place, so you don’t have to repeat it elsewhere.
2. Flexible Object Creation : Easily create different types of objects by passing parameters to the factory method.
3. Reusable Code : The factory method can be reused throughout the application, simplifying object creation.
4. When to Use? : When object creation is complex or involves a lot of logic, or when object types may change in the future.