While developing a plugin, we might have to display error messages if something went terrible wrong and the user just can go on, like if their version of PHP is too old.
One way to do it is with
die('error'), which kills the page and displays the error message. However, this doesn’t look very pretty and no HTML is printed. Just an empty document with the text ‘error’.
Instead, we could use WordPress build-in function
wp_die(), which creates a better looking error message, in which we can provide helpful links etc.
<?php wp_die( __("Your PHP version isn't up-to-date, please <a href='http://php.net'>update</a>.") ); ?>