To turn on Error Reporting in PHP, you can put these two lines of PHP codes anywhere on your PHP script file. Just make sure that the codes is put on the top most of your script.

To display all PHP errors and notices:

<?php
    ini_set('display_errors', 1);
    error_reporting(E_ALL|E_STRICT);
?>

To display all PHP errors only:

<?php
    ini_set('display_errors', 1);
    error_reporting(E_ALL);
?>

To turn off error reporting:

<?php
    error_reporting(0);
?>