It is said that deprecated functions used in plugins & themes can crash a wordress website while upgrading to newer version, I want to see an example of deprecated function that can cause a crash.
Can someone show me an example?
The following files hold the deprecated functions:
Take a look at them and then through their replacement functions, where the calls to
Normally a crash shouldn't happen. In the "real" PHP world, you'd get an
E_DEPRECATED Warning. In WordPress you'll get a
trigger_error() return caused by
_deprecated_function() calls. The second
trigger_error() argument isn't used, so it defaults to
E_USER_NOTICE and won't stop your application from running.
You can turn this off either by using
define( 'WP_DEBUG', false ); or by using a MU-Plugin that sets the filter to false:
<?php defined('ABSPATH') or exit; /** Plugin Name: (#105686) Turn off deprecated Warnings */ add_filter( 'deprecated_function_trigger_error', '__return_false' );