Summarize PHP interview questions 2023

1. PHP
2. MySQL
3. Linux
4. NoSQL
5. Development environment
6. Code version control

PHP

- PHP arrays, array functions, array traversal, and predefined arrays (must be included in the interview). 
- PHP object-oriented, magic method, encapsulation, inheritance, polymorphism.Design patterns, including (simple interest, factory, iterator, decorator, command, strategy). 
- Regular expression, the meaning of each label, email address, URL, label matching, regular function (must be included in the interview). 
- PHP exception handling (level, error log, control error output)(must appear in the interview). 
- PHP time function, date calculation function. 
- File system, record log, directory, file traversal, upload, multi-method to get file extension, file reference method, and reference function difference. (Interview must be given). 
- Conversation control, mainly about the principle. The solution to the problems of session and cookie in distributed applications. 
- PHP template engine, commonly used template engine features, good and bad aspects of MVC. 
- PHP security processing, filter function. 
- Use of XML. 
- Processing of PHP strings, including escaping (safety), encoding, interception, positioning, conversion with arrays, processing functions, etc. (Interview must be given). 
- Socket programming, various protocols, header, meaning of curl parameters. 
- The meaning of the network status code, commonly used (204, 304, 404, 504, 502). 
- Apache configuration file, PHP configuration file, the meaning of each meaning field. 
- The noun meanings of various network attacks (SQL attack, XSS, CSRF, DDos), prevention measures. 
- The processing function of url, get the part specified by url.
- Variable value and reference. 
- Variable type conversion and judgment type method. 
- PHP operator priority, generally writes the operation result of the operator. 
- Function parameter passing in PHP, closure, judgment output echo, print is a function, etc. 

MySQL

- How to use PDO, why use.
- mysql optimization, table splitting, etc. 
- transaction processing, sql statement processing efficiency, etc. 
- data table field type, difference between the same type, how to choose, int( 10) The difference with int(11), etc. 
- The data structure used by the database index, draw the data structure.
- Basic sql statement writing (generally let you write association and subquery statements).
- Index creation, advantages and disadvantages, the leftmost principle.
- Storage engines, commonly used ones, advantages and disadvantages, differences, principles (must be revealed in the interview).
- Processing method of sql injection.
- mysql processing function (encapsulated in PHP).

Linux

- The use of common commands, the use of vim editor.
- View commands for process, cpu and other information.
- View commands in the file (mainly related to statistical information).
- The use of Shell, command operation
- Usage of awk
- The shell kills all php-fpm processes.

NoSQL

- The application scenario of Redis, combined with the Weibo business to tell its specific application.
- The difference between Redis and MC support data, which data structure storage both support, the more write the better.
- The principle of Redis persistent storage is different from the application of Mysql. How to maintain the relationship between persistent data and memory data synchronization (Redis synchronization mechanism)
- Performance comparison between Redis and MC in concurrent state.
- MC's memory management mechanism, how to allocate memory space when a piece of data needs to be stored
- Redis's memory management mechanism, what are the differences from MC.

Development environment

- New and abandoned features in PHP8 
- Why use PHP8, where is PHP8 fast 
- Understanding of exceptions and errors in PHP8

Code version control

- The use command of git, for example: write the version rollback command.
- The difference between git and svn.
- How to carry out multi-branch development, including multi-person development collaboration, segmented testing, and online.

Continuing...