title: Regex for fixed length string of character A followed by character B
body: <p>I'm trying to find a halfway decent regex for a string exactly 8 characters long. Those 8 characters should be comprised of a's followed by b's.</p>
  
  <p>Another way of putting this would be a{n}b{8-n} where n=0...8</p>
  
  <p>Example Matching Strings:
  aaaaaaaa
  abbbbbbb
  aaaabbbb
  bbbbbbbb</p>
  
  <p>Example Non-Matching Strings:
  bbbbaaaa
  aaaabaaa</p>