Wordpress判断用户是否登录或留言过

<?php
if ( is_user_logged_in() ) {
echo 'Welcome, registered user!';
} else {
echo 'Welcome, visitor!';
}
?>

<?php if($_COOKIE["comment_author_email_" . COOKIEHASH]!="" || is_user_logged_in()) {?>
    //do something
<?php } else{ ?>
    //do something
<?php } ?>