The object-oriented design principles and patterns in software development refer to following some common and proven guiding principles and practical methods that are conducive to improving software quality and maintainability during the software design process. The purpose of object-oriented design principles and patterns is to achieve high cohesion, low coupling, reusable, scalable, and testable software systems.
Object-oriented design principles refer to some basic norms that should be followed when defining classes, interfaces, and inheritance relationships, such as the single responsibility principle, the opening and closing principle, the Liskov substitution principle, the dependency inversion principle, and the interface isolation principle. These principles can help us avoid designing overly complex, confusing, and fragile software structures, but design clear, concise, and stable software structures.
Object-oriented design patterns refer to some mature and reusable solutions that can be referred to when solving some common and recurring software design problems, such as singleton mode, factory mode, observer mode, strategy mode, etc. These patterns can help us improve code reusability, flexibility, and readability, as well as reduce code modification costs and risks.
Object-oriented design principles and patterns are the concrete embodiment of object-oriented programming ideas. They are not mandatory specifications, but a programming art and skill, which need to be flexibly used according to specific project requirements and environments. Learning and mastering object-oriented design principles and patterns can improve our software development ability and level, and also allow us to write more elegant and higher-quality code.