Include files in PHP. Include and require code examples

The include statement includes an external file with php code into the program. So, for example, let’s define the hello.php file.

Let’s create a file for an example, call it hello.php and add the code below:

$age = 24;

Now let’s attach this file to our main one and use the $age variable:

include "hello.php";//include our file
 
$name = "Ben";
echo $name . '=' . $age;

require "hello.php";//include our file

include once, require once

include the file only once:

include once "hello.php";
require once "hello.php";

In large applications, the number of included files can be quite large. However, the built-in function spl_autoload_register()