This repository contains classic design patterns, each with its own implementation and explanation. Design patterns are well-established solutions to common software design problems. They provide a structured approach to solving recurring design challenges and promote code reusability, maintainability, and scalability.
- Adapter Pattern
- Decorator Pattern
- Factory Pattern
- Iterator Pattern
- Observer Pattern
- Singleton Pattern
- State Pattern
- Strategy Pattern
Description: The Adapter Pattern allows the interface of an existing class to be used as another interface. It is often used to make existing classes work with others without modifying their source code.
Use Case: Suppose you have a legacy class with an incompatible interface, and you want to use it with a new system. The Adapter Pattern helps create an adapter class that bridges the gap between the two interfaces, allowing them to work together seamlessly.
Description: The Decorator Pattern is used to dynamically add new behaviors or responsibilities to objects without altering their code. It involves creating a set of decorator classes that are used to wrap concrete components.
Use Case: When you need to extend the functionality of objects in a flexible and reusable way, such as adding features to a text editor or customizing beverages in a coffee shop application, the Decorator Pattern can be beneficial.
Description: The Factory Pattern provides an interface for creating objects, but it allows subclasses to alter the type of objects that will be created. It is often used to encapsulate object creation logic.
Use Case: In scenarios where you need to create objects without exposing the instantiation logic, like creating different types of payment methods or document formats, the Factory Pattern can help manage object creation.
Description: The Iterator Pattern is used to provide a way to access the elements of an aggregate object sequentially without exposing its underlying representation. It separates the traversal of a collection from its structure.
Use Case: When you have a collection of objects (e.g., lists, trees, or custom data structures) and you want to provide a uniform way to iterate through them, the Iterator Pattern simplifies the process.
Description: The Observer Pattern defines a one-to-many relationship between objects, ensuring that when one object changes state, its dependents (observers) are notified and updated automatically.
Use Case: In scenarios where multiple objects need to be informed of changes in another object, such as updating UI components in response to changes in data, the Observer Pattern is an excellent choice.
Description: The Singleton Pattern restricts a class from instantiating multiple objects and ensures that only one instance exists. It provides a global point of access to that instance.
Use Case: When you want to ensure there's only one instance of a class responsible for managing shared resources, like database connections, configuration settings, or a logging system, the Singleton Pattern is a valuable choice.
Description: The State Pattern allows an object to alter its behavior when its internal state changes. It encapsulates the state-specific behavior and makes it interchangeable.
Use Case: In applications where an object's behavior changes based on its internal state (e.g., a vending machine with different states for money insertion and product selection), the State Pattern simplifies state management.
Description: The Strategy Pattern defines a family of algorithms, encapsulates each one, and makes them interchangeable. It allows the algorithm to vary independently from clients that use it.
Use Case: When you need to select an algorithm from a family of algorithms dynamically, such as sorting algorithms in a search engine or payment methods in an e-commerce application, the Strategy Pattern is an effective choice.