What is the difference between the Template Method Pattern and the Strategy Pattern?

What is the difference between the Template Method Pattern and the Strategy Pattern?

The Template Method Pattern defines the skeleton of an algorithm in a method, allowing subclasses to redefine certain steps without changing the algorithm's structure. In contrast, the Strategy Pattern enables selecting an algorithm's behavior at runtime by encapsulating algorithms in separate classes.

Can you give me an example of each pattern?

Sure! For the Template Method Pattern, consider a class DataProcessor with a method processData(), which calls abstract methods like readData() and writeData(). Subclasses implement these methods. For the Strategy Pattern, imagine a SortingContext class that uses a SortingStrategy interface. You can have different strategies like QuickSort or BubbleSort that can be set at runtime.

When should I use one pattern over the other?

Use the Template Method Pattern when you have a fixed algorithm structure but need flexibility in certain steps. Opt for the Strategy Pattern when you want to switch between different algorithms dynamically.

Are there any drawbacks to using these patterns?

Yes, the Template Method Pattern can lead to a rigid structure if overused, while the Strategy Pattern can increase the number of classes, making the system more complex.