How do I hide several lines if php variable is empty? [duplicate]

Question

As a learner in PHP, I'm struggling to hide from displaying several lines, if a chosen variable is empty. I can get this to work on a basic level, but am lost when the content to be hidden gets more complicated. The concept I am aiming at is this:

<?php if (isset($g1)) { ?>
((This part should not display if variable $g1 is empty))
<?php } ?>

My code looks like this:

<?php if (isset($g1)) { ?>
<a href="img/g1.png"  class="lightbox"  rel="tooltip" data-original-title="<?php print $g1; ?>" data-plugin-options='{"type":"image"}'>
<img class="img-responsive img-rounded wbdr4" src="img/g1.png">
</a>
<?php } ?>

In the above, the tooltip does not display when variable g1 is empty, but the rest does. I'm new here so, I hope I've formatted my question correctly. Help appreciated.

Answer 1

<?php if (isset($g1) && $g1!='') { ?>
<a href="img/g1.png"  class="lightbox"  rel="tooltip" data-original-title="<?php print $g1; ?>" data-plugin-options='{"type":"image"}'>
<img class="img-responsive img-rounded wbdr4" src="img/g1.png">
</a>
<?php } ?>