1. Single mode:

Singleton pattern aims to ensure that there is only one instance of a class and provide a global access point. It is often used when a globally unique instance is needed, such as a recorder or a database connection.

2. Factory mode:

The factory pattern is determined by defining the interface for creating objects, but the specific implementation of the objects is delayed to subclasses or specific factory classes. It can hide the logic of object creation and make the code more flexible and extensible.

3. Observer mode:

The observer pattern defines a one-to-many dependency. When the state of an object changes, all its dependent objects will be automatically notified and updated. This mode is usually used in event-driven systems, such as user interface updates of GUI applications.

4. Adapter mode:

The adapter pattern allows the interface of a class to be converted into the interface expected by the client. It is usually used to convert between incompatible interfaces so that originally incompatible classes can work together.

5. Strategic model:

Policy pattern defines a set of algorithms or behaviors that can be replaced with each other, and encapsulates each algorithm in an independent class, so that they can be replaced with each other. This mode can dynamically select the algorithm at runtime, and improve the flexibility and maintainability of the code.

This is only a small part of common design patterns, and there are many other design patterns in software development, each of which has different uses and advantages. According to the specific application scenarios and requirements, choosing the appropriate design pattern can improve the reusability, maintainability and expansibility of the code.

The above contents were carefully arranged by Zhu Bajie. Com, I hope I can help you.