Best way to display only distinct value from multiple div tags with same class name

Best way to display only distinct value from multiple div tags with same
class name

How can i display only distinct value from multiple div tags with same
class name
<div class="categories">cat 1</div>
<div class="categories">cat 1</div>
<div class="categories">cat 2</div>
<div class="categories">cat 2</div>
<div class="categories">cat 2</div>
<div class="categories">cat 3</div>
<div class="categories">cat 3</div>
I would like to display only distinct value and hide the rest
cat 1
cat 2
cat 3