wordpress if user logged in get current username code example

Example 1: wp get logged in user id

<?php
	$user_id = get_current_user_id();
?>

Example 2: How do I display logged-in username IF logged-in? site:wordpress.stackexchange.com

<?php global $current_user; wp_get_current_user(); ?>
<?php if ( is_user_logged_in() ) { 
 echo 'Username: ' . $current_user->user_login . "\n"; echo 'User display name: ' . $current_user->display_name . "\n"; } 
else { wp_loginout(); } ?>