for

The for tag loops over items in a sequence (array or hash).

For example, to loop over a list of blog posts you could do the following:

{% for post in posts %}
    <h2>{{ post.postTitle }}</h2>
{% endfor %}

The "post" value will hold each value in the posts array as it's looped through.

The loop variable

Inside of a for loop block you have access to some special variables. These variables are not accessible outside of the for loop.

The loop variable holds an array of values.

Iterate over a sequence of numbers or letters.

If you need to iterate over a sequence of numbers you can use the .. operator.

{% for i in 0..10 %}
    {{ i }}<br>
{% endfor %}

The above will output all numbers from 0 to 10 with each on a new line.

You can do a similar thing with letters.

{% for letter in 'a'...'z' %}
    {{ letter }}<br>
{% endfor %}

Variable	Description
loop.index	The current iteration of the loop starting at 1. {{ loop.index }}
loop.index0	The current iteration of the loop starting at 0. {{ loop.index0 }}
loop.revindex	The number of iterations from the end of the loop starting at 1. {{ loop.revindex }}
loop.revindex0	The number of iterations from the end of the loop starting at 0. {{ loop.revindex0 }}
loop.first	Holds whether or not the current iteration is the first iteration. True if it's the first iteration, false if it's not. {% if loop.first %} {% endif %}
loop.last	Holds whether or not the current iteration is the last iteration. True if it's the last iteration, false if it's not. {% if loop.last %} {% endif %}
loop.length	Holds the number of items in the loop sequence. {{ loop.length }}
loop.parent	Holds the parent context; the variable being looped through. {% for post in posts %} {{ loop.parent\|debug('parent') }} {% endfor %} In the above code loop.parent would hold the posts value.

The loop.length, loop.revindex, loop.revindex0 and loop.last variables are not available when looping with a condition.

Adding a loop condition

You cannot force breaking out of a loop, however, you can add a condition that allows you to skip items in the loop.

The following would skip all users which are not active.

<ul>
    {% for user in users if user.active %}
        <li>{{ user.username }}</li>
    {% endfor %}
</ul>

Note, do not use the loop variable within the condition. For example, adding a condition like the following won't work as the index is only incremented when the condition is true. In this case the condition will never match.

{% for item in items if loop.index > 4 %}
{% endfor %}

The else clause

If no looping will occur because the sequence is empty, then you can output a replacement by using else.

{% for post in posts %}
    <p><a href="{{ post.url }}>{{ post.postTitle }}</a></p>
{% else %}
    <p>There are no posts.</p>
{% endfor %}

Iterating over keys

By default, the for loop will only iterate over the values of the sequence. You can use the keys filter to iterate over only the array keys.

{% for key in array|keys %}
   ...
{% endfor %}

Iterating over both keys and values

Below is how you would iterate over both the keys and values of an array.

{% for key, user in users %}
    <p>{{ key }}: {{ user.name }}
{% endfor %}

Iterate over a subset

If you wanted to iterate over a portion of the array then you can achieve this with the slice filter.