title: two simple string operation in objective-c (shift operating and iterating)
body: <p>I want to manipulate NSString in obj-c here is what I want to do :</p>
  
  <p>iterate a string though a for-each / for loop and shift left (&lt;&lt;) each character of NSString
  but I don't know how should I iterate through the NSString's characters and how to use shift operator in obj-c.</p>
  
  <p>I'm fairly new in objective-c .</p>
  
  <p>regards</p>