comment_(old_status)_to_(new_status) action-hook . WP 2.7.0

Fires when the comment status is in transition from one specific status to another.

The dynamic portions of the hook name, $old_status, and $new_status, refer to the old and new comment statuses, respectively.

Usage

add_action( 'comment_(old_status)_to_(new_status)', 'action_function_name_1839' );
function action_function_name_1839( $comment ){
	// action...
}

$comment(WP_Comment)

Comment object.

Where the hook is called

do_action( "comment_{$old_status}_to_{$new_status}", $comment );

Where in WP core the hook is used WordPress