• first of all, correct one point: MVC is just a structure of most WEB applications (a guiding principle for designing the framework). It itself and what you call the namespace namespace (specifically, it belongs to a new technology, new features) are two-dimensional things, so the two cannot be compared equally. In other words, most current frameworks use the principle of MVC to design code architecture, and namespace is a technology commonly used in the current PHP development process.
• the first way you describe should, as I understand it, be the development of OPP (above is function , so it should not be encapsulated in the class). The encapsulation of classes can be regarded as the development way of OOP . And to achieve what you call "introducing the required functions in the least redundant way" actually has little to do with the two. no, no, no. When you split and combine methods (functions) in an appropriate way, you will always find the results you want to achieve. no, no, no. OPP you can only use require or include to load the files and functions you need, and the dependencies between files need to be maintained manually. However, under the general OOP , the dependencies between classes still need to be maintained manually, so there is no qualitative difference between them, so there is no specific pros and cons.
• next, let's analyze your specific puzzles. the problem you throw out is actually so huge that it can be regarded as a subject that can be studied. No, no, no. In fact, the reverse of "introducing the required functionality in the least redundant way" is to "find the best way to improve the reuse of code and reduce redundancy". Many design patterns need to be combined with practical problems to achieve this goal. What you describe as "deciding which classes to introduce according to the router" seems to convey dependency injection (Denpdency Injection, DI). Dependency injection is essentially a call to a class, but it leaves the dependency of the class to the dependency injection container to manage. You can take a closer look at DIP , IoC and DI , and you should be able to understand it. In addition, you can also try to design Interface , abstract and then add trait to to achieve the effect you need.