title: How to format numbers to same number of digits, 0-padded?
body: <p>I have several strings of different length</p>
  
  <pre><code>"2323"
  "245"
  "353352"
  </code></pre>
  
  <p>I need to convert them to string of the same size such as:</p>
  
  <pre><code>"0002323"
  "0000245"
  "0353352"
  </code></pre>
  
  <p>How can I automatically add the correct number of 0s in front of each string ?</p>
  
  <p>thanks</p>