For loops

These are not filters, as they cannot be used alone. Only in a for loop.

Given array:

my_array:
  - 1
  - 2
  - 3

For loop modifiers

Limit

Get the first N items.

{% for item in page.my_array limit: 2 %}
    {{ item }}
{% endfor %}

Skip the first items and start at the Nth item.

{% for item in page.my_array offset: 2 %}
   {{ item }}
{% endfor %}

Combine offset and limit e.g. start at 2nd item and get 2 items.

{% for item in page.my_array offset: 2 limit: 2 %}
   {{ item }}
{% endfor %}

See also All Filters page for slice filter.

Reversed

{% for item in page.my_array reversed %}
    {{ item }}
{% endfor %}

For loop variables

Index

Index of the current iteration.

Use .index to start at one or .index0 to start at zero. And first and last for whether at the start or end of the loop.

forloop.index
forloop.index0
forloop.first
forloop.last 

e.g.

{% for item in page.my_array %}
    {{ forloop.index }}  <!-- e.g. 1, 2, 3 -->
    {{ forloop.index0 }} <!-- e.g. 0, 1, 2 -->
    {{ forloop.last }}  <!-- e.g. false, false, true -->
{% endfor %}

Using last is useful if you are rendering a separator. Like a comma between JSON values or a pipe symbol | beween items in a menu.

{
{% for key_value in page.my_array %}
    {{ key_value[0] | jsonify }}: {{ key_value[1] | jsonify }}
    {% unless forloop.last %},{% endunless %}
{% endfor %}
}

To get:

{
  "abc": "123",
  "def": "xyz"
}

Length

{{ forloop.length }}