WordPressPHP
wp_json_encode() vs json_encode() in WordPress
WordPress ships its own JSON wrapper. Here's what it does differently and why you should use it inside WordPress instead of native json_encode().
WordPressPHPAJAX
A WordPress detail that can silently break your AJAX
Forgetting wp_die() at the end of a WordPress AJAX handler looks harmless. It isn't. Here's why it breaks responses and what to do instead.