title: RegExp for minimum 4 numbers and minimum 1 character
body: <p>I'm trying to test if an input has at least 4 number and 1 character in it. I have this which works, but only when the characters are in the order <code>0000a</code>, I wanted it to match no matter what the order, so <code>00a00</code>, <code>a0000</code>, <code>aa00a00a</code> would all match the pattern.</p>
  
  <pre><code>[0-9]{4,}[a-zA-Z]{1,}
  </code></pre>
  
  <p>What do I need to change? I tried <code>[a-zA-Z0-9]{5,}</code> but then things like <code>aaaaa</code> and <code>00012</code> matched, which is no good.</p>