title: UILabel wont show the previous characters, only the last letter
body: <p>Goal is to enumerate every character in the String. That is 'w' will appear then after 1 sec will be replaced by 'h' then 'e' then 'n'.
  Problem my label only shows the last letter. </p>
  
  <p>What i did:
      1. drag a label and a button on the PlayViewController.
      2. create the property for Label
      3. create action for button</p>
  
  <p>In my PlayViewController.h:</p>
  
  <pre><code>#import &lt;UIKit/UIKit.h&gt;
  
  @interface PlayViewController : UIViewController
  
  @property (strong, nonatomic) IBOutlet UILabel *listChar;
  
  - (IBAction)startGame:(id)sender;
  
  @end
  </code></pre>
  
  <p>In my PlayViewController.m:</p>
  
  <pre><code>#import "PlayViewController.h"
  
  @interface PlayViewController ()
  
  @end
  
  @implementation PlayViewController
  
  NSString *word;
  NSTimer *myTimer;
  
  - (void)viewDidLoad 
  {
      [super viewDidLoad];
      // Do any additional setup after loading the view.
      self.listChar.text = @" ";
      word = @"when";
  
  }
  
  - (IBAction)startGame:(id)sender {
      myTimer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(listLetter:) userInfo:nil repeats:YES];
  }
  
  
  -(void) listLetter:(NSTimer*) myTimer {
      for(int i=0; i&lt;[word length]; i++){
          unichar letter = [word characterAtIndex: i];
          self.listChar.text = [NSString stringWithFormat:@"%C", letter];
      }
  }
  
  @end
  </code></pre>