Get next and previous elements out of an array in liquid

Question

Short version:

I want to add 1 to a number in a liquid template and use the result as an array index.

{% capture plus_one %}{{ 0 | plus: 1 }}{% endcaptur         


        

Answer 1

{% for category in site.categories %}
    {% assign catg_name = category.first %}
    {% if catg_name == page.category %}
        {% assign catg_posts = category.last %}
    {% endif %}
{% endfor %}
{% for post in catg_posts %}
    {% if post.title == page.title %}
        {% unless forloop.last %}
            {% assign next = catg_posts[forloop.index] %}
            

            ←{{ next.title }}
            
        {% endunless %}
        {% unless forloop.first %}
            

            {{ prev.title }}→
            
        {% endunless %}
    {% endif %}
    {% assign prev = post %}
{% endfor %}

As you have mentioned you can save and use the previous iteration value for the previous post link( in my case I use it as the next post link since I don't want the default newest-first order ). For the next array element you can use forloop.index. This is the 1-based index of the for loop and will give you the next item of a zero-based array.