There are times you might want to reference a particular file in another file. These is mostly common in OOP. PHP provides function which can be used to reference another file from a calling file. These function are include() and require() and we will be looking at them shortly. These functions help in creating functions, headers, footers, or elements that can be reused on multiple pages. This will help developers to make it easy to change the layout of complete website with minimal effort. If there is any change required then instead of changing thousand of files just change included file.
The Include Function
The include() takes all the text in a specified file and copies it into the file that uses the include function. If there is any problem in loading a file then the include() function generates a warning but the script will continue execution. The include() has another variant called include_once(). What include_once does is to make sure the file is only included once so as to avoid referencing same file multiple times.

<?php
include('header.php');
?>

<?php
include_once('footer.php');
?>

The Require Function
The require() function takes all the text in a specified file and copies it into the file that uses the include function. Unlike the include(), the require() will terminate the execution of the script if there is any problem in loading the file. The require() also has another variant called the require_once(). This does exactly as the include_once does: make sure the file is only referenced once.

<?php
require('db.php');
?>

<?php
require_once('import.php');
?>

Conclusion
Now you have seen how to make use of the includes functions provided by PHP and seen their difference. I recommend using the require_once() when you are including a file because the script should not continue execution while your included failed.

I hope you find this tutorial helpful. You can leave your comments, questions and suggestions in the comment box below.
source: http://tutorialslodge.com/php-file-inclusion/

Good insight for newbies, but I agree not with you on supporting the use of require_once()
What if you wanted to include ad? If course I'll use include() cuz I want it execution to proceed if the file doesn't exists + that I might still call it in the same script.
So it depends on what and how you want to solve a problem.

tresz:
Good insight for newbies, but I agree not with you on supporting the use of require_once()
What if you wanted to include ad? If course I'll use include() cuz I want it execution to proceed if the file doesn't exists + that I might still call it in the same script.
So it depends on what and how you want to solve a problem.

u right there

Hello guys, what's wrong with this function

function testRequire($file) {
return require_once ($file .'html');

}

I prefer using the include()

CRAZYMADMAN:
Hello guys, what's wrong with this function

?

CRAZYMADMAN:
Hello guys, what's wrong with this function

Me thinks U're not invoking the function after setting it up. What exactly is that code supposed to do? What error message do U keep getting? I'm trying not to assume.

53cur3m0d3:

Me thinks U're not invoking the function after setting it up. What exactly is that code supposed to do? What error message do U keep getting? I'm trying not to assume.

the problem is that when you try to use it to include a html file, it takes it to the very top of the page thereby disrupting any template structure already in place! I have gotten the solution, though

CRAZYMADMAN:


the problem is that when you try to use it to include an html file, it takes it to the very top of the page thereby disrupting any template structure already in place! I have gotten the solution, though

Great... U might wanna share though

53cur3m0d3:

Great... U might wanna share though

function testRequire($file) {
ob_start();
require_once ($file .'html');
return ob_get_clean();

}

CRAZYMADMAN:





function testRequire($file) {
ob_start();
require_once ($file .'html');
return ob_get_clean();

}

The Output Buffering function! Thanks...

53cur3m0d3:

The Output Buffering function! Thanks...

don't mention it.


But that gave enough headaches sha

php's version of import