If you’ve ever needed to see if an action has been fired and/or how many times it has been fired, there’s a handy function that will return the amount of times an action has been fired.
This function can come in handy when building things that could be extended by other developers that may want to filter out something.
I noticed it use in the WP-Shortcake plugin (https://github.com/wp-shortcake/shortcake/blob/7c9f5483b9ca10d38fa9412b264a2e6d1e12d528/inc/class-shortcode-ui.php)
The plugin introduces a Shortcode Interface on post edit pages, but only if a specific shortcode ui has been registered.
To register a UI for a plugin, an array of settings must be passed to the “register_shortcode_ui” action, but if that’s not done, the Shortcake UI is never loaded, all because of the “did_action” check.
This is a handy way to make code extendable, but avoid unnecessary bloat.