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.

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 scope of JavaScript determines the accessibility scope of variables, which are divided into global, function and block-level scope; the context determines the direction of this and depends on the function call method. 1. Scopes include global scope (accessible anywhere), function scope (only valid within the function), and block-level scope (let and const are valid within {}). 2. The execution context contains the variable object, scope chain and the values of this. This points to global or undefined in the ordinary function, the method call points to the call object, the constructor points to the new object, and can also be explicitly specified by call/apply/bind. 3. Closure refers to functions accessing and remembering external scope variables. They are often used for encapsulation and cache, but may cause

C ABI is the underlying rule that the compiler follows when generating binary code, which determines mechanisms such as function calls, object layout, name adaptation, etc. 1. It ensures that different compilation units interact correctly, 2. Different compilers or versions may adopt different ABIs, affecting dynamic library links, STL transfers, virtual function calls, etc. 3. Cross-platform development, long-term system maintenance, third-party library use and other scenarios need to pay special attention to ABI consistency, 4. ABI can be controlled through macro definitions and compilation options, and use tools to view the symbol table to judge consistency.