title: Doctrine array vs simple_array vs json_array
body: <p>I am using symfony and doctrine as my ORM.</p>
  
  <p>For available types I have:</p>
  
  <ul>
  <li><strong>array</strong></li>
  <li><strong>simple_array</strong></li>
  <li><strong>json_array</strong></li>
  </ul>
  
  <p>I am wondering what the difference is between each of them: when do I use one or the other? </p>
  
  <p>Can I have a demonstration for each of them to illustrate the differences?</p>
  
  <p>I already use simple_array in some applications but I find I don't understand formType... (Or maybe I'm not using it well!? )</p>
  
  <p><em>To illustrate my question</em>, here is an example:</p>
  
  <p>I have an Task that I have to run on specific days
  So I created <strong>TaskEntity</strong> with <strong>days</strong> attribute</p>
  
  <p>Days would be:</p>
  
  <pre><code>$days = array(
      1=&gt;true,
      2=&gt;true,
      3=&gt;true,
      4=&gt;true,
      5=&gt;true,
      6=&gt;false,
      7=&gt;false
  );
  </code></pre>
  
  <p>But I have no idea which of the above types to choose ...</p>