Question

I want to add the post tags into its div class so I can add specific CSS for different types of tags.

Answer 1

If you want to output the tag name(s) of the article being viewed into a div, do that :

<div class="
<?php
$posttags = get_the_tags();
if ($posttags) {
  foreach($posttags as $tag) {
    echo $tag->name . ' '; 
  }
}
?>
">
...
</div>

If you want to output the tag name that’s being display (let’s say the tag’s page), do that :

<div class="<? echo single_tag_title(); ?>">
.....
</div>