title: iPhone - Truncate String to Last Four
body: <p>All,</p>
  
  <p>I can't seem to find the answer I'm looking for using search so I'll ask it.</p>
  
  <p>I need to pull the last four digits of a credit card number out and set it into another string. It needs to account for the variances in credit card number lengths (i.e. 16 numbers or 15 numbers, etc)</p>
  
  <p>i.e. if the number was "1234567890123456" I would want to set a new string as "3456". </p>
  
  <p>Thanks</p>