The same code often needs to be called on multiple pages. This can be done by first placing the code inside a separate file and then including that file using the include statement. This statement takes all the text in the specified file and includes it in the script, just as if the code had been copied to that location. Just like echo, include is a special language construct and not a function, so parentheses should not be used.
When a file is included parsing changes to HTML mode at the beginning of the target file and resumes PHP mode again at the end. For this reason any code inside ...