Wordpress通过php获取用户角色[关闭]

I'm creating a page in my wordpress site, with a list of the users and need to get the title of their role with php. But, every thing I tried failed. Anyone who can help please.

The function that returns the current user roles :

function display_user_roles(){
    $user_id = get_current_user_id();
    $user_info = get_userdata( $user_id );
    $user_roles = implode(', ', $user_info->roles);
    return $user_roles;
}

To use it in your code:

<?php echo display_user_roles(); ?>