title: splitting random strings in iphone
body: <p>I have a string with random numbers, </p>
  
  <p>like <strong>"12345678912234"</strong></p>
  
  <p>I want to split it into 4 parts, like,</p>
  
  <p><strong>string1 = 123</strong></p>
  
  <p><strong>string2 = 456</strong></p>
  
  <p><strong>string3 = 7891</strong></p>
  
  <p><strong>string4 = 2234</strong></p>
  
  <p>anybody has any idea??</p>
  
  <p>I've tried using NSRange but I cannot get it. May be I'm using it wrong.</p>
  
  <p>I also tried using <code>substringToIndex</code> but it failed too.</p>