(PHP) Show Social Link, But Only If There is Data in the Field

I am trying to figure out how I can showcase the user's social links as defined in their profiles. I am using the following code...

function contact_function() {
	// Shortcode Contents
	$user_id_from_email = get_user_id_from_string( get_blog_option($thisblog, 'admin_email'));
	$user_info = get_userdata($user_id_from_email);
	$member = $user_info->sponsor;

	return
	'Name: ' . $user_info->display_name . "<br />" .
	'Member #: ' . $member . "<br />" .
	'Email: ' . $user_info->user_email . "<br />" .
	'' . "<a target='_blank' href='$user_info->facebook'><img src='https://www.yldist.com/ms/images/social/social-icons-facebook.jpg'></a>" . " " .
	'' . "<a target='_blank' href='$user_info->googleplus'><img src='https://www.yldist.com/ms/images/social/social-icons-googleplus.jpg'></a>" . " " .
	'' . "<a target='_blank' href='$user_info->twitter'><img src='https://www.yldist.com/ms/images/social/social-icons-twitter.jpg'></a>" . ""
	;
}
add_shortcode( 'contact-page', 'contact_function' );

I can not figure out how to hide the icons if the user has not inserted a valid link into their profile area.