title: Regular Expression for a string that contains one or more letters somewhere in it
body: <p>What would be a regular expression that would evaluate to true if the string has one or more letters anywhere in it.</p>
  
  <p>For example:</p>
  
  <p><code>1222a3999</code> would be true</p>
  
  <p><code>a222aZaa</code>  would be true</p>
  
  <p><code>aaaAaaaa</code>  would be true</p>
  
  <p>but:</p>
  
  <p><code>1111112())--</code> would be false</p>
  
  <p>I tried: <code>^[a-zA-Z]+$</code> and <code>[a-zA-Z]+</code> but neither work when there are any numbers and other characters in the string.</p>