What is the difference between include and require statements?

1. phpProgramWhen you execute require (), the file will be read only once, so it is often placed at the beginning of the program. After the file is imported, PHP will re-compile the webpage file to make the introduced file a part of the original webpage.

2. When the PHP program executes include (), the file is read every time. Therefore, it is often used in the Process Control Section, such as condition judgment or loop.

3. Require (): unconditional inclusion. If the file does not exist, a fatal error is reported. The script is stopped.

4. Include (): conditional inclusion. If the file does not exist, a warning is provided, but the script continues to run.

5. We recommend that you use require_once () and include_once () to check whether the file contains duplicates.