Found a total of 10000 related content
What is the use of the << operator in PHP?
Article 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
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1089
What is the difference between an interface and an abstract class in C#, and when would you use each?
Article Introduction：In C#, interfaces are used to define behavior contracts that need to be implemented by multiple unrelated classes, suitable for multiple inheritance, dependency injection and unit testing; abstract classes are used for closely related classes of shared logic, supporting fields, access modifiers and constructors. 1. The interface defines behavioral contracts, supports default implementations, but is mainly used for structural constraints; 2. The abstract class contains abstract and concrete methods, providing shared logic; 3. The interface allows multiple implementations, without fields and constructors, and members are exposed by default; 4. The abstract class can only inherit a single one, and can have private members and constructors; 5. The interface is suitable for plug-in architecture and API design, and the abstract class is suitable for "is-a" relationship modeling; 6. It can be used in combination, and the abstract class implements the interface to provide basic implementation. Selection depends on design objectives: interface focus capability, abstract class
2025-06-22
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187
What are interfaces in PHP?
Article Introduction：Interfaces are used in PHP to define contracts that classes must follow, specifying methods that classes must implement, but do not provide specific implementations. This ensures consistency between different classes and facilitates modular, loosely coupled code. 1. The interface is similar to a blueprint, which specifies what methods should be used for a class but does not involve internal logic. 2. The class that implements the interface must contain all methods in the interface, otherwise an error will be reported. 3. Interfaces facilitate structural consistency, decoupling, testability and team collaboration across unrelated classes. 4. Using an interface is divided into two steps: first define it and then implement it in the class. 5. Classes can implement multiple interfaces at the same time. 6. The interface can have constants but not attributes. PHP7.4 supports type attributes but is not declared in the interface. PHP8.0 supports named parameters to improve readability.
2025-06-23
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269
How do you implement custom session handling in PHP?
Article Introduction：Implementing custom session processing in PHP can be done by implementing the SessionHandlerInterface interface. The specific steps include: 1) Creating a class that implements SessionHandlerInterface, such as CustomSessionHandler; 2) Rewriting methods in the interface (such as open, close, read, write, destroy, gc) to define the life cycle and storage method of session data; 3) Register a custom session processor in a PHP script and start the session. This allows data to be stored in media such as MySQL and Redis to improve performance, security and scalability.
2025-04-24
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704
What is Reflection API in PHP and give practical examples?
Article Introduction：The Reflection API in PHP allows you to check and manipulate code at runtime. 1) It implements reflection function through classes such as ReflectionClass. 2) The working principle of the reflection API depends on the Zend engine. 3) The basic usage includes checking the class structure. 4) Advanced usage can implement dependency injection containers. 5) Common errors need to be handled through try-catch. 6) Performance optimization suggestions include cache reflection results and avoiding unnecessary reflections.
2025-04-04
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590
What are the differences between Interfaces and Abstract Classes in PHP?
Article Introduction：In PHP, the difference between interfaces and abstract classes is mainly reflected in the definition, inheritance model and implementation method. 1. The interface only defines method signatures (PHP8.1 supports default methods), emphasizing "what should be done", while abstract classes can contain abstract methods and concrete implementations, emphasizing "how to implement some functions". 2. Classes can implement multiple interfaces, but can only inherit one abstract class, so interfaces are more flexible when combining multiple behaviors. 3. The interface method is exposed by default and cannot have attributes. Abstract classes support arbitrary access control, attributes, constructors and destructors. 4. Use interfaces when a unified API is required or when an interchangeable component is designed; use abstract classes when a shared state or logically related classes. The selection basis is: the interface is used to define the contract, and the abstract class is used to share the implementation logic.
2025-06-23
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365
What are PSR Standards and Why Are They Important in PHP?
Article Introduction：PSR is a PHP standard recommendation, formulated by the PHP framework interoperability group, aiming to improve code consistency, readability and cross-frame compatibility. Common standards include: 1. Basic PSR-1 specifications, such as labels and naming conventions; 2. PSR-4 automatic loading standards, defining class and path mapping; 3. PSR-12 extended coding style, refined format rules; 4. PSR-3 log interface, supporting log library replacement; 5. PSR-7 HTTP message interface, convenient for middleware and API development. Its value is reflected in improving multi-project collaboration efficiency, enhancing tool support, simplifying integration, and improving code expertise. Application methods include using Composer to configure PSR-4, automatically format code with the help of tools, and manually following PSR
2025-07-10
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261
Dave The Diver: How To Catch Spider Crabs
Article Introduction：In Dave The Diver, there are some creatures that are not easy to catch. Or, catch alive that is. The spider crab is one of those very species, making it seem like the only way to bring these crustaceans back up to land is to viciously crack them up w
2025-01-10
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777
Prepare for Interview Like a Pro with Interview Questions CLI
Article Introduction：Prepare for Interview Like a Pro with Interview Questions CLI
What is the Interview Questions CLI?
The Interview Questions CLI is a command-line tool designed for JavaScript learners and developers who want to enhance their interview
2025-01-10
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1407
Soft Deletes in Databases: To Use or Not to Use?
Article Introduction：Soft Deletes: A Question of DesignThe topic of soft deletes, a mechanism that "flags" records as deleted instead of physically removing them, has...
2025-01-10
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1026
