For

Loop over each item in a sequence. For example, to display a list of users provided in a variable called users:

<h1>Members</h1>
<ul>
  {% for user in users %}
    <li>{{ user.username|e }}</li>
  {% endfor %}
</ul>

A sequence can be either an array or an object implementing the Iterator interface.

If you do need to iterate over a sequence of numbers, you can use the .. operator (as of Twig 0.9.5):

{% for i in 0..10 %}
  * {{ i }}
{% endfor %}

The above snippet of code would print all numbers from 0 to 10.

It can be also useful with letters:

{% for letter in 'a'..'z' %}
  * {{ letter }}
{% endfor %}

The .. operator can take any expression at both sides:

{% for letter in 'a'|upper..'z'|upper %}
  * {{ letter }}
{% endfor %}

If you need a step different from 1, you can use the range filter instead:

{% for i in 0|range(10, 2) %}
  * {{ i }}
{% endfor %}

Inside of a for loop block you can access some special variables (if you don't need them, you can add without loop at the end of the forstatement for a small speed boost):

VariableDescription
loop.index The current iteration of the loop. (1 indexed)
loop.index0 The current iteration of the loop. (0 indexed)
loop.revindex The number of iterations from the end of the loop (1 indexed)
loop.revindex0 The number of iterations from the end of the loop (0 indexed)
loop.first True if first iteration
loop.last True if last iteration
loop.length The number of items in the sequence
loop.parent The parent context

The loop.lengthloop.revindexloop.revindex0, and loop.last variables are only available for PHP arrays, or objects that implement the Countable interface (as of Twig 0.9.7).

Unlike in PHP it's not possible to break or continue in a loop.

If no iteration took place because the sequence was empty, you can render a replacement block by using else:

<ul>
  {% for user in users %}
    <li>{{ user.username|e }}</li>
  {% else %}
    <li><em>no user found</em></li>
  {% endfor %}
</ul>

By default, a loop iterates over the values of the sequence. You can iterate on keys by using the keys filter:

<h1>Members</h1>
<ul>
  {% for key in users|keys %}
    <li>{{ key }}</li>
  {% endfor %}
</ul>

You can also access both keys and values:

<h1>Members</h1>
<ul>
  {% for key, user in users %}
    <li>{{ key }}: {{ user.username|e }}</li>
  {% endfor %}
</ul>

On Twig before 0.9.3, you need to use the items filter to access both the keys and values ({% for key, value in users|items %}).