Display something only once in a loop in twig - php

Question

I have some pics that I want to display by months.
But I my code I get the month on top of every pics.
How to avoid this ?
{% for media in medias %}
{% if media.date|date("m") == 10 and media.assetpath is not null %}
<h2>Photos october</h2>
<div class="col-xs-2">
<img class="img-responsive" src="{{ asset(media.assetpath) }}"/>
</div>
{% elseif media.date|date("m") == 11 and media.assetpath is not null %}
<h2>Photos november</h2>
<div class="col-xs-2">
<img class="img-responsive" src="{{ asset(media.assetpath) }}"/>
</div>
{% else %}
<h2>other month</h2>
<div class="col-xs-2">
<img class="img-responsive" src="{{ asset(media.assetpath) }}"/>
</div>
{% endif %}
{% endfor %}

Answer 1

Assuming that medias is an array sorted by date, the problem can be solved using a temporary variable:
{% set last_month = '' %}
{% for media in medias %}
{% set month = media.date('F')|lower %}
{% if last_month and month != last_month %}
<h2>Photos {{ month }}</h2>
{% endif %}
{% set last_month = month %}
<div class="col-xs-2">
<img class="img-responsive" src="{{ asset(media.assetpath) }}"/>
</div>
{% endfor %}
However, I would rather generate a more appropriate structure, e.g.:
$media = [
'November' => [
[ /* media 1 */],
[ /* media 2 */],
// ...
],
// ...
];
With this structure, the template code will look much cleaner:
{% for month, media in medias %}
<h2>Photos {{ month }}</h2>
{% for m in media %}
<div class="col-xs-2">
<img class="img-responsive" src="{{ asset(m.assetpath) }}"/>
</div>
{% endfor %}
{% endfor %}