Factory Pattern

Factory pattern is one of the most popular creational pattern. In factory pattern, we hide the object creation logic from the consumer of the factory. We use an interface to return the newly created object. Let's understand this by an example.

We will create:

1. An interface called Animal
2. Classes, Cat, Dog, Mouse
3. A factory class called AnimalFactory

Animal interface:

interface Animal {
    fun move()
}

Cat, Dog, Mouse classes:

class Cat : Animal {
    fun move() {
        print("Cat moves")
    }
}

class Dog : Animal {
    fun move() {
        print("Dog moves")
    }
}

class Mouse : Animal {
    fun move() {
        print("Mouse moves")
    }
}

AnimalFactory class:

class AnimalFactory {
    fun getAnimal(name: String): Animal? {
        return when (name) {
            "cat" -> Cat()
            "dog" -> Dog()
            "mouse" -> Mouse()
            else -> null
        }
    }
}

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Last update: August 13, 2023