How to include content of a PHP file into another PHP file ?

There are multiple ways to include the content of a PHP file into another PHP file:

• include(): The include() function is used to include a PHP file into another PHP file. If the file is not found, it will generate a warning message but the script will continue to execute.

Example:

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

• require(): The require() function is similar to include() but if the file is not found, it will generate a fatal error and stop the script execution.

Example:

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

• include_once(): The include_once() function is used to include a PHP file only once. If the file has already been included, it will not be included again.

Example:

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

• require_once(): The require_once() function is similar to include_once() but if the file is not found, it will generate a fatal error and stop the script execution.

Example:

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

In all of the above examples, "file.php" is the name of the PHP file that you want to include.