title: Variable name from _multiple_ variables in Twig
body: <p>I'm using Opencart and I have a really useful plugin from an older version in php. I noticed that twig isn't that hard and I tried to convert the php code into twig. Simple ifs/for loops/echos were easy enough, but the original author uses dynamically created variable names.</p>
  
  <p>I have seen examples using attribute and _context when the dynamic part comes from just one variable. But what happens when the variable name consists of 2, 3, or more variable parts?</p>
  
  <p>This is an actual example (and there are many more like this)</p>
  
  <pre><code>${'var_' . $extension['name'] . '_' . $geo_zone['geo_zone_id'] . '_' . $customer_group['customer_group_id'] . '_order_total_sort_order'};
  </code></pre>
  
  <p>Is this something that can be achieved or is it a way of thinking totally incompatible with twig?</p>
  
  <p>EDIT:
  I understand how we use the value of a dynamically created variable. But is it possible to initialize it without knowing the various components in the first place? Or check if such a variable even exists? In my particular case the variables are created by user defined fields and then used freely, also passing through an if check.</p>
  
  <p><code>&lt;select name="var_&lt;?= $geo_zone['geo_zone_id']; ?&gt;_&lt;?= $group['group_id']; ?&gt;_tax_class_id"&gt;
      &lt;option value="0" &lt;?php if(${'var_' . $geo_zone['geo_zone_id'] . '_' . $group['group_id'] . '_tax_class_id'} == 0){ echo 'selected'; } ?&gt;&gt;&lt;?= $text_none; ?&gt;&lt;/option&gt;
  &lt;/select&gt;</code></p>
  
  <p>I honestly have no idea how this can be turned into twig.</p>