To allow PHP services to pass through the Windows 11 firewall, you need to create inbound rules to open the corresponding port or program. 1. Determine the port that PHP is actually listening. If the built-in server is started with php-Slocalhost:8000, the port is 8000. If using Apache or IIS, it is usually 80 or 443. 2. Open the advanced settings of "WindowsDefender Firewall", create a new inbound rule, select "Program" or "Port", fill in the PHP or Web server path or specify the port number. 3. Select Allow Connections, check the applicable network configuration file, name the rules and add a description. The IP addresses that are allowed to access, such as local network or specific IP, can be restricted through the scope. Safety

High-frequency trading is one of the most technologically-rich and capital-intensive areas in the virtual currency market. It is a competition about speed, algorithms and cutting-edge technology that ordinary market participants are hard to get involved. Understanding how it works will help us to have a deeper understanding of the complexity and specialization of the current digital asset market. For most people, it is more important to recognize and understand this phenomenon than to try it yourself.

RAII is an important technology used in resource management in C. Its core lies in automatically managing resources through the object life cycle. Its core idea is: resources are acquired at construction time and released at destruction, thereby avoiding leakage problems caused by manual release. For example, when there is no RAII, the file operation requires manually calling fclose. If there is an error in the middle or return in advance, you may forget to close the file; and after using RAII, such as the FileHandle class encapsulates the file operation, the destructor will be automatically called after leaving the scope to release the resource. 1.RAII is used in lock management (such as std::lock_guard), 2. Memory management (such as std::unique_ptr), 3. Database and network connection management, etc.

There are four common methods to obtain the first element of std::vector: 1. Use the front() method to ensure that the vector is not empty, has clear semantics and is recommended for daily use; 2. Use the subscript [0], and it also needs to be judged empty, with the performance comparable to front() but slightly weaker semantics; 3. Use *begin(), which is suitable for generic programming and STL algorithms; 4. Use at(0), without manually null judgment, but low performance, and throw exceptions when crossing the boundary, which is suitable for debugging or exception handling; the best practice is to call empty() first to check whether it is empty, and then use the front() method to obtain the first element to avoid undefined behavior.

The core of PHP's development of AI text summary is to call external AI service APIs (such as OpenAI, HuggingFace) as a coordinator to realize text preprocessing, API requests, response analysis and result display; 2. The limitation is that the computing performance is weak and the AI ecosystem is weak. The response strategy is to leverage APIs, service decoupling and asynchronous processing; 3. Model selection needs to weigh summary quality, cost, delay, concurrency, data privacy, and abstract models such as GPT or BART/T5 are recommended; 4. Performance optimization includes cache, asynchronous queues, batch processing and nearby area selection. Error processing needs to cover current limit retry, network timeout, key security, input verification and logging to ensure the stable and efficient operation of the system.

Bit operation can efficiently implement the underlying operation of integers, 1. Check whether the i-th bit is 1: Use n&(1

Functions are the basic unit of organizing code in C, used to realize code reuse and modularization; 1. Functions are created through declarations and definitions, such as intadd(inta,intb) returns the sum of the two numbers; 2. Pass parameters when calling the function, and return the result of the corresponding type after the function is executed; 3. The function without return value uses void as the return type, such as voidgreet(stringname) for outputting greeting information; 4. Using functions can improve code readability, avoid duplication and facilitate maintenance, which is the basic concept of C programming.

The C standard library helps developers improve code quality by providing efficient tools. 1. STL containers should be selected according to the scene, such as vector suitable for continuous storage, list suitable for frequent insertion and deletion, and unordered_map is suitable for fast search; 2. Standard library algorithms such as sort, find, and transform can improve efficiency and reduce errors; 3. Intelligent pointers unique_ptr and shared_ptr effectively manage memory to avoid leakage; 4. Other tools such as optional, variant, and function enhance code security and expressiveness. Mastering these core functions can significantly optimize development efficiency and code quality.