title: transform the numbers to letters using php
body: <p>I store the number <code>1 2 3 4</code> as the answer to multiple choice questions in MySQL database,</p>
  
  <p>But I want to display them in <code>a b c d</code> on web page. </p>
  
  <p>I'm using PHP, how can I transform the numbers to letters using PHP?</p>
  
  <pre><code>echo "
  &lt;h2&gt;question&lt;/h2&gt;
  &lt;p&gt;".$row[0]."&lt;/p&gt;
  &lt;h2&gt;answer&lt;/h2&gt;
  &lt;p&gt;".$row[1]."&lt;/p&gt;"; 
  </code></pre>
  
  <p>The <code>row[1]</code> is <code>{1,2,3,4}</code> now, I want it turn to <code>{A,B,C,D}</code>.</p>
  
  <p>Can any one please have a look and tell me how to do it?</p>