Including many PHP scripts may cause a problem. As include statement does not check for the scripts that are already included. Example:
<?php
include (‘add.php’);
include (‘add.php’);
echo add (2, 2);
?>
Here you will get the error: Cannot redeclare add()
Hence here you should use an include_once statement.
Now by using include_once statement:
<?php
include_once (‘add.php’);
include_once (‘add.php’);
echo (2,2);
?>
This will give the output 4, after execution.
