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 %} |
| 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 %} |
| 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 %} 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.