What is the difference between Singleton and Factory design patterns?

What is the difference between Singleton and Factory design patterns?

The Singleton pattern ensures a class has only one instance and provides a global point of access to it. In contrast, the Factory pattern is used to create objects without specifying the exact class of object that will be created.

Can you give me an example of when to use each pattern?

Sure! Use Singleton when you need a single instance, like a configuration manager. Use Factory when you want to create objects that share a common interface but may have different implementations, like different types of shapes.

What are the advantages of using these patterns?

Singleton reduces memory usage by limiting instances, while Factory promotes loose coupling and easier testing by abstracting object creation.

Are there any drawbacks to using these patterns?

Yes, Singleton can introduce global state, making testing harder. Factory can add complexity if overused, leading to unnecessary abstraction.