FROM CACHE - en_header

Concat is not working

Shopify Partner
15 1 3

I'm trying to add categories to the blocks and then want to retrieve unique categories(not repetitive categories). Using concat but it's not working and i don't know how to achieve it. 

Below is my code and please help me out: 


    {% assign categoryNames = '' | split: '' %}
    <div class="faq-wrapper">
       {% for block in section.blocks %}
        {% case block.type %}
		{% when 'faq_block' %}
      	{% assign categoryNames = categoryNames | concat: block.settings.category_name %}
      	{% endcase %}
      {% endfor %}
      <div class="one-third">
          {% for categoryName in categoryNames %}
          <li class="list-group-item">
            <a class="filter-button" href="">{{categoryName}}</a>
          {% endfor %}


Append is working fine. But i want to use concat which is not working. When i try to retrieve it, it gives me an empty array. I don't know what horrible mistake i'm making. Spent more than two hours. and couldn't find any solution.

Reply 1 (1)
Shopify Partner
15 1 3

when i try to read values from the categoryNames, it returns nothing. I don't know why it's empty.