title: Regular Expression to find numbers with same digits in different order
body: <p>I have been looking for a regular expression with Google for an hour or so now and can't seem to work this one out :(</p>
  
  <p>If I have a number, say:</p>
  
  <p><code>2345</code></p>
  
  <p>and I want to find any other number with the same digits but in a different order, like this:</p>
  
  <p><code>2345</code></p>
  
  <p>For example, I match</p>
  
  <p><code>3245</code> or <code>5432</code> (same digits but different order)</p>
  
  <p>How would I write a regular expression for this?</p>