title: How can I increase 0000 by 1 and keep formatting?
body: <pre><code>$i=0000;
  while($i&lt;=1231)
  {
    print "$i";
    $i++;
  }
  </code></pre>
  
  <p>I want it to display <code>0001</code>,
  <code>0002</code>,
  <code>0003</code>,
  <code>0004</code>,
  but instead it prints: 
  <code>0</code>,
  <code>1</code>,
  <code>2</code></p>
  
  <p>Does anyone know why this isn't working?<br>
  Thank you in advance.</p>