Course Introduction：A metaclass is a "class that creates a class", and the default is to create a class; when you define a class, Python actually calls type('ClassName',(),{}) to generate a class object. Custom metaclasses can be processed before and after class creation by inheriting the type and overwriting new or init methods, such as forcing the implementation of methods, automatically registering subclasses, interface verification, modifying attributes/methods, implementing design patterns, etc. For example, check whether the class implements required_method. Metaclasses are suitable for framework development, but attention should be paid to avoiding abuse, complex debugging, over-encapsulation and other problems.
2025-07-02 comment 0 570
Course Introduction：This article explains class and object creation in PHP 7. It details the differences between classes (blueprints) and objects (instances), illustrates object-oriented programming principles (encapsulation, abstraction, inheritance, polymorphism), a
2025-03-10 comment 0 427
Course Introduction：Classes and objects in PHP realize code organization and reuse through encapsulation, methods and access control. Define the class to use the class keyword, which contains attributes and methods, such as classCar{private$color; publicfunctionsetColor($newColor){$this->color=$newColor;}}; create objects to use the new keyword, such as $myCar=newCar(); access attributes and methods through the -> operator; public, protected, and private control access permissions to implement data encapsulation; the constructor __construct() is used for initialization
2025-07-16 comment 0 264
Course Introduction：Class decorator implements the __call__ method to make class instances available as decorators, suitable for saving state and encapsulation logic. 1. The basic structure is to define a class with __init__ and __call__ methods. The former receives functions and the latter performs pre- or post-operations; 2. The class decorator with parameters receives parameters during initialization and returns the wrapper function in __call__ to realize repeated calls or conditional control of the function; 3. The functions, methods or class itself can be unified, such as permission checking, decorator judges user rights based on the context; 4. Supports decorator chains, and multiple class decorators execute from bottom to top in the order of overlay, which is suitable for debugging, performance analysis and other scenarios.
2025-07-03 comment 0 539
Course Introduction：In PHP, implementing polymorphism can be achieved through method rewriting, interfaces, and type prompts. 1) Method rewriting: Subclasses override parent class methods and perform different behaviors according to object type. 2) Interface: The class implements multiple interfaces to realize polymorphism. 3) Type prompt: Ensure that the function parameters are specific to the type and achieve polymorphism.
2025-05-20 comment 0 1136
Course Elementary 13926
Course Introduction：Scala Tutorial Scala is a multi-paradigm programming language, designed to integrate various features of object-oriented programming and functional programming.
Course Elementary 82482
Course Introduction："CSS Online Manual" is the official CSS online reference manual. This CSS online development manual contains various CSS properties, definitions, usage methods, example operations, etc. It is an indispensable online query manual for WEB programming learners and developers! CSS: Cascading Style Sheets (English full name: Cascading Style Sheets) is an application used to express HTML (Standard Universal Markup Language).
Course Elementary 13264
Course Introduction：SVG is a markup language for vector graphics in HTML5. It maintains powerful drawing capabilities and at the same time has a very high-end interface to operate graphics by directly operating Dom nodes. This "SVG Tutorial" is intended to allow students to master the SVG language and some of its corresponding APIs, combined with the knowledge of 2D drawing, so that students can render and control complex graphics on the page.
Course Elementary 24731
Course Introduction：In the "AngularJS Chinese Reference Manual", AngularJS extends HTML with new attributes and expressions. AngularJS can build a single page application (SPAs: Single Page Applications). AngularJS is very easy to learn.
Course Elementary 27566
Course Introduction：Go is a new language, a concurrent, garbage-collected, fast-compiled language. It can compile a large Go program in a few seconds on a single computer. Go provides a model for software construction that makes dependency analysis easier and avoids most C-style include files and library headers. Go is a statically typed language, and its type system has no hierarchy. Therefore users do not need to spend time defining relationships between types, which feels more lightweight than typical object-oriented languages. Go is a completely garbage-collected language and provides basic support for concurrent execution and communication. By its design, Go is intended to provide a method for constructing system software on multi-core machines.
There is a problem with the final call of php to implement image verification code?
2022-05-05 01:22:00 0 8 1274
2018-09-10 10:02:37 0 0 1392
Class library, how to use it, is there any detailed method?
2018-07-12 11:54:40 0 6 1398
How to disable PHP reporting SQL errors?
2023-09-05 17:14:24 0 1 819
Laravel Modal does not return data
2024-03-29 10:31:31 0 1 666
