add all users to custom buddypress group

gistfile1.php

function add_users_to_bpgroup() {   
	$group_id = 1;
	$users = get_users(); // all users

	foreach ( $users as $user ) {
		var_dump(groups_join_group($group_id, $user->ID ));
	}
}

add_action ( 'wp_enqueue_scripts', 'add_users_to_bpgroup' );