Source

File: wp-includes/comment-template.php

function get_comment_ID() { // phpcs:ignore WordPress.NamingConventions.ValidFunctionName.FunctionNameInvalid
	$comment = get_comment();

	/**
	 * Filters the returned comment ID.
	 *
	 * @since 1.5.0
	 * @since 4.1.0 The `$comment_ID` parameter was added.
	 *
	 * @param int        $comment_ID The current comment ID.
	 * @param WP_Comment $comment    The comment object.
	 */
	return apply_filters( 'get_comment_ID', $comment->comment_ID, $comment );  // phpcs:ignore WordPress.NamingConventions.ValidHookName.NotLowercase
}