title: How to left pad integers with a formatter with dots?
body: <p>I know we can left-pad integers with a formatter like this:</p>
  
  <pre><code>String.format("%7d", 234);   // "    234"
  String.format("%07d", 234);  // "0000234"
  String.format("%015d", 234); // "0000000000000234"
  </code></pre>
  
  <p>But, how to replace the zeros by dots (like a plain text content index)?</p>
  
  <pre><code>String.format("%.13d", 234); // doesn't work
  </code></pre>
  
  <p>I want to produce this:</p>
  
  <pre><code>..........234
  </code></pre>
  
  <p>I know I can use a loop to add the dots, but I want to know if there is a way to do this with a formatter.</p>