What is the difference between dynamic classes and static classes in PHP?

The difference between dynamic classes and static classes in PHP: 1. Static classes are frequently used and dynamic classes are seldom used; 2. Static classes are fast and occupy memory, while dynamic classes are relatively slow, but releasing them immediately after calling can save memory, so you can choose according to your own needs; 3. For servers with large memory, static setting will improve efficiency. Compared with servers with small memory, dynamic mode will end redundant processes and reclaim and release some memory.

Operating system of this course: Windows S10 system, PHP version PHP8.1.3, Dell G3 computer.

The difference between dynamic classes and static classes in PHP

Static methods are stored in memory during the whole application, which is fast but takes up memory.

class A { public static string b() { return "Hello"; } }

usage

A.b(); //Easy to call

A dynamic method can only call a method in a class by declaring an instance of the class first.

class A{ public string b() { return "Hello"; }}

usage

A a = new a(); a.b();

Generally, static methods are used for frequently used methods, and dynamic methods are used for seldom used methods.

Static speed is fast, occupying memory. Dynamic speed is relatively slow, but releasing the class immediately after the call can save memory, and you can choose whether to use dynamic method or static method according to your own needs.

Therefore, the dynamic mode is recommended to be used on servers with less memory because it will end redundant processes and can reclaim and release some memory. It is recommended to set it according to the load of the server, and the appropriate value is between 5 and 10.

For servers with large memory, setting it to static will improve efficiency. Because the php-fpm process will be switched on and off frequently, the static effect will be better if the memory is large enough.

The main problem of static method is data synchronization. If you don't save private variables in the class of your static method, there will be no problem. It is best that all the data to be manipulated by the package are passed to the method in the form of parameters.

Static methods are class methods, and you don't need to create class instances when calling them.

Dynamic methods are statically bound to subclasses, not inherited.

The static method modifies the state of the class, while the dynamic method modifies the state of each object, which is also their important difference.

The instantiation call of a dynamic class exists in the life cycle of the class. When the class is gone, the corresponding instance is gone, and the corresponding method is gone. The static class is not. As long as you refer to the namespace of that static class, it will always exist until you exit the system.