Object-oriented design patterns

Object-oriented design principles: seven Principles

1, single duty principle SRP

Definition: Every class in a system should have only one responsibility

Benefits: cohesion, low coupling

2, open and closed principle OCP

Definition: Open for extension, close for modification

Benefits: Adaptability and flexibility, stability and continuity, reusability and maintainability

3, Richter replacement principle LSP

Definition: Wherever the parent class appears, it can be replaced with its subclasses without affecting the function

4, dependency inverted principle dip

Definition: High-level modules should not rely on the underlying modules, both should rely on their abstraction;

Abstraction should not depend on detail; detail should depend on abstraction.

Benefits: Improve the stability of the program, maintainability, scalability.

5, interface isolation principle ISP

Definition: Using multiple specialized interfaces is better than using a single total interface.

Benefit: Do not force new features to implement unwanted approaches

6, Dimitri Principle lop

Definition: An object should have as little knowledge of other objects as possible

Benefits: Reduced COUPLING

Disadvantages: Reduced communication efficiency, resulting in a large number of intermediary classes

7, combination/aggregation multiplexing principle carp

Definition: Preferential use of the combination to make the system more flexible, followed by the consideration of inheritance, to achieve the purpose of reuse

Benefit: Fewer dependencies are required for composite multiplexing

Composite multiplexing can be performed dynamically during run time

Cons: The system will have more objects to manage

Object-oriented design patterns