WordPress at a glance
filter is not described

wp_update_comment_data filter-hook . WP 4.7.0

Filters the comment data immediately before it is updated in the database.

Note: data being passed to the filter is already unslashed.

Usage

add_filter( 'wp_update_comment_data', 'filter_function_name_6419', 10, 3 );
function filter_function_name_6419( $data, $comment, $commentarr ){
	// filter...

	return $data;
}
$data(array)
The new, processed comment data.
$comment(array)
The old, unslashed comment data.
$commentarr(array)
The new, raw comment data.

Where the hook is called

wp_update_comment()
wp_update_comment_data
wp-includes/comment.php 2232
$data = apply_filters( 'wp_update_comment_data', $data, $comment, $commentarr );

Where the hook is used (in WP core)

Does not used.