Function error_get_last() will return an error information even if the error is hidden because you've used character @, because of the "error_reporting" directive in the php.ini file, or because you've used function error_reporting().
Examples:
<?php
error_reporting(E_ALL ^ E_NOTICE);
$y = $x;
$err = error_get_last();
var_export($err);
?>
Will display: array ( 'type' => 8, 'message' => 'Undefined variable: x', 'file' => 'test.php', 'line' => 4, )
<?php
$y = @$x;
$err = error_get_last();
var_export($err);
?>
Will display: array ( 'type' => 8, 'message' => 'Undefined variable: x', 'file' => 'test.php', 'line' => 4, )