shounoop / design-pattern

design-pattern

I. Overview

Design patterns are reusable solutions to common problems that software encounter while designing and developing software applications. These patterns provide a standard approach to solve a particular problem, which has been proven over time to be effective and efficient.

• There are three types of design patterns:

  1. Creational Patterns

  • These patterns are used to create objects in a way that is suitable for a particular situation.
  • Examples of creational patterns incluse: Singleton, Factory Method, Abstract Factory, Builder, and Prototype.

  2. Structural Patterns

  • These patterns are used to provide a way to organize objects in a particular structure.
  • Examples of structural patterns include: Adapter, Bridge, Composite, Decorator, Facade, Flyweight, and Proxy.

  3. Behavioral Patterns

  • These patterns are used to manage communication and behavior between objects in a system.
  • Examples of behavioral patterns incluse: Chain of Responsibility, Command, Interpreter, Iterator, Mediator, Memento, Observe, State, Strategy, Template Method, and Visitor.

--> Design patterns are a valuable tool for software developers as they provide proven solutions to common problems. --> By using design patterns, developers can save time and effort, reduce errors, and improve the quanlity of their software applications.

II. Detail

1. Creational Patterns

1.1. Factory Pattern

• This pattern is used to create objects without specifying the exact class of object that will be created.
• The basic idea is to define an interface for creating objects, but allow subclasses to decide which class to instantiate. --> The factory pattern provides an elegant way to encapsulate object creation logic and make code more modular and flexible. --> It also helps to decouple client code from concrete classes, making it easier to change the implementation of the interface without affecting the client code.

2. Structural Patterns

2.1. Adapter Pattern

• This pattern allows imcompatible interfaces to work together by wrapping an existing class with a new interface that client code can use.

2.2. Bridge Pattern

• This pattern decouples an abstraction from its implementation so that they can vary independently.
• It involves using an interface or abtract class to separate the implementation from the abstraction.

2.3. Composite Pattern

• This pattern is used to represent part-whole hierarchies of objects.
• It allows clients to treat individual objects and groups of objects uniformly.
• In other words, the Composite pattern allows you to treat a single object or a group of objects in the same way.

2.4. Decorator Pattern

• This pattern allows for dynamic behavior modification

2.5. Facade Pattern

• This pattern simplifies complex systems

2.6. Flyweight Pattern

• This pattern reduces memory usage by sharing common data