What are the differences between the Composite and Decorator design patterns?

What are the differences between the Composite and Decorator design patterns?

The Composite pattern allows you to compose objects into tree structures to represent part-whole hierarchies. The Decorator pattern, on the other hand, allows behavior to be added to individual objects, either statically or dynamically, without affecting the behavior of other objects from the same class.

Can you give me an example of each pattern?

Sure! For the Composite pattern, think of a graphic system where shapes can be grouped. A Shape interface can have Circle and Rectangle classes, and a CompositeShape class that holds a collection of shapes. For the Decorator pattern, consider a coffee shop where you can add milk or sugar to a basic Coffee object. Each addition is a decorator that enhances the coffee's functionality.

When should I use one pattern over the other?

Use the Composite pattern when you need to treat individual objects and compositions uniformly. Use the Decorator pattern when you want to add responsibilities to individual objects dynamically.

Are there any drawbacks to using these patterns?

Yes, the Composite pattern can lead to a design that is overly complex if not managed well, while the Decorator pattern can result in a large number of small classes, making the system harder to understand.