Software Design Patterns Questions Long
The Template Method design pattern is a behavioral design pattern that defines the skeleton of an algorithm in a superclass, allowing subclasses to provide specific implementations for certain steps of the algorithm. It promotes code reuse and provides a way to define a common structure for a group of related algorithms.
The Template Method pattern consists of two main components: the abstract class (or superclass) and the concrete classes (or subclasses). The abstract class defines the overall algorithm and declares abstract methods that represent the steps of the algorithm. These abstract methods are then implemented by the concrete classes to provide specific behavior for each step.
The Template Method pattern follows the "Hollywood Principle" - "Don't call us, we'll call you." In other words, the abstract class controls the overall flow of the algorithm and calls the concrete methods implemented by the subclasses when necessary.
A scenario where the Template Method pattern can be applied is in the development of a game. Let's consider a simple game where players take turns to play a card game. The game consists of multiple steps such as shuffling the deck, dealing cards, playing a turn, and determining the winner.
In this scenario, we can define an abstract class called "CardGame" that represents the overall structure of the game. The "CardGame" class would have a template method called "playGame" that defines the sequence of steps for playing the game. The abstract class would also declare abstract methods such as "shuffleDeck," "dealCards," "playTurn," and "determineWinner."
The concrete classes, such as "PokerGame" and "BlackjackGame," would extend the "CardGame" class and provide specific implementations for the abstract methods. For example, the "PokerGame" class would implement the "shuffleDeck" method to shuffle the deck of cards in a poker-specific way, while the "BlackjackGame" class would implement it differently for blackjack.
By using the Template Method pattern, we can ensure that the overall structure of the game remains consistent across different card games, while allowing each game to have its own specific implementation for certain steps. This promotes code reuse, reduces duplication, and provides a clear separation of concerns between the overall game structure and the specific game logic.