how do i set a conditional statement here?

<ul>
    <li class="artist-website"><a href="<?php=$artist_website?>" target="_blank"></a></li>
    <li class="artist-youtube"><a href="http://youtube.com/<?php=$artist_youtube?>" target="_blank"></a></li>
    <li class开发者_JAVA百科="artist-twitter"><a href="http://twitter.com/<?php=$artist_twitter?>" target="_blank"></a></li>
</ul>

I want to add an if exists statement before each of the 'li' items. For example, if "artist-website" exists, then echo <li class="artist-website"><a href="<?php=$artist_website?>" target="_blank"></a></li>

How can I do make this work?

<ul>
  <?php if(isset($artist_website){ ?> <li class="artist-website">...</li> <?php } ?>
  ...
</ul>

Or if(!empty($artist_website)), depending how your variables are setup.

As simple as:

<?php if (/* exists */) : ?>
    <li class="artist-website"><a href="<?php echo $artist_website ?>" target="_blank"></a></li>
<?php endif; ?>

Ah, I understand what you're asking. Here is a link showing how to check if a website is available. The other 2 comments mainly showed you how to set up the if statement.

http://css-tricks.com/snippets/php/check-if-website-is-available/

EDIT: unless you are checking if a variable is set or not... then it would be:

if (isset($var)) {

// do this

}