Get user role

/**
 * Gets WordPress user role.
 * 
 * @see: https://core.trac.wordpress.org/ticket/22624
 * @see: https://wordpress.stackexchange.com/questions/131814/if-the-current-user-is-an-administrator-or-editor/324768#324768
 */
if ( ! function_exists( 'get_user_role' ):
function get_user_role( $user_id = 0 ) {
    $user = ( $user_id ) ? get_userdata( $user_id ) : wp_get_current_user();
    return current( $user->roles );
}
endif;