


Explanation of the difference between include() and require() in PHP_PHP Tutorial
require is used as <font face="NSimsun">require("MyRequireFile.php");</font>
. This function is usually placed at the front of the PHP program. Before the PHP program is executed, it will first read in the file specified by require and make it a part of the PHP program web page. Commonly used functions can also be introduced into web pages in this way.
include is used as <font face="NSimsun">include("MyIncludeFile.php");</font>
. This function is generally placed in the processing part of flow control. The PHP program webpage only reads the include file when it reads it. In this way, the process of program execution can be simplified.
The two of them have exactly the same purpose, and it doesn’t necessarily have to be which one is in the front and which one is in the middle. The most fundamental difference between them is the way they handle errors.
If there is an error in require a file, then the program will interrupt execution and display a fatal error
If there is an error in include a file, then the program will not end, but will continue to execute and display a Warning error.
The following are supplements:
1. include has a return value, but require does not.
2. include() includes and runs the specified file. When the processing fails, include() generates a warning. The imported program code will be executed, and these programs will have and call the source file when executed. to the same variable scope as the include() statement. You can import static pages from the same server.
3. The function of include_once() is almost the same as include()
The only difference is that include_once() will first check whether the file to be imported has been imported elsewhere in the program. If it has been passed, it will not be imported again (this function is sometimes very important. For example, if the file to be imported declares some functions that you have defined yourself, then if you import this file repeatedly in the same program , an error message will occur when importing for the second time, because PHP does not allow functions with the same name to be declared twice).
4. require() will read the contents of the target file and replace itself with the read contents. If the processing fails, require() will cause a fatal error.
This reading and substitution action occurs when the PHP engine compiles your program code, not when the PHP engine starts executing the compiled program code (the way the PHP 3.0 engine works is to compile a line Execute one line, but this has changed since PHP 4.0. PHP 4.0 first compiles the entire program code, and then executes the compiled program code at once. No program code will be executed during the compilation process. ). require() is usually used to import static content, while include() is suitable for importing dynamic program code.
5. Like include_once(), require_once() will first check whether the content of the target file has been imported before. If so, the same content will not be imported again.
5. require is an unconditional inclusion, that is, if require is added to a process, require will be executed first regardless of whether the condition is true or not.
7. require is usually placed at the front of the PHP program. Before the PHP program is executed, it will first read in the file specified by require and make it a part of the PHP program web page. Commonly used functions can also be introduced into web pages in this way.
8. Include is generally placed in the processing part of the process control. The PHP program webpage only reads the included file when it reads it. This method can simplify the process of program execution.
The difference between require(), include(), require_once() and include_once()

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.


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