How to hide PHP Warnings and Notices in WordPress
<?php
//functions.php
error_reporting(0);
@ini_set('display_errors', 0);
//or
//wp-config.php
ini_set('log_errors','On');
ini_set('display_errors','Off');
ini_set('error_reporting', E_ALL );
define('WP_DEBUG', false);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false);
?>