title: local declaration hides instance variable / unused variables warnings
body: <p>I have a "local declaration hides instance variable" error for “secondsLeft” and “unused variable” for hours, minutes and seconds. Thank you in advance for any help you can provide on this one.</p>
  
  <p>.h file</p>
  
  <pre><code>#import &lt;Foundation/Foundation.h&gt;
  #import &lt;UIKit/UIKit.h&gt;
  #import "BT_viewController.h"
  
  
  
  @interface BT_screen_blank : BT_viewController {
  
      NSTimer *timer;
      IBOutlet UILabel *myCounterLabel;
  }
  
  @property (nonatomic, retain) UILabel *myCounterLabel;
  @property (nonatomic) int secondsLeft;
  @property (nonatomic) int minutes;
  @property (nonatomic) int hours;
  @property (nonatomic) int seconds;
  
  -(void)updateCounter:(NSTimer *)theTimer;
  -(void)countdownTimer;
  
  @end
  </code></pre>
  
  <p>.m file</p>
  
  <pre><code> @implementation BT_screen_blank
   @synthesize myCounterLabel;
   @synthesize secondsLeft, hours, minutes, seconds;
  
  
   //viewDidLoad
   -(void)viewDidLoad{
  [BT_debugger showIt:self:@"viewDidLoad"];
  [super viewDidLoad];
  
  
  int hours, minutes, seconds;
  int secondsLeft;
  
  
  secondsLeft = 16925;
  [self countdownTimer];
  }
  
  - (void)updateCounter:(NSTimer *)theTimer {
  if(secondsLeft &gt; 0 ){
      secondsLeft -- ;
      hours = secondsLeft / 3600;
      minutes = (secondsLeft % 3600) / 60;
      seconds = (secondsLeft %3600) % 60;
      myCounterLabel.text = [NSString stringWithFormat:@"%02d:%02d:%02d", hours, minutes,          seconds];
  }
  else{
      secondsLeft = 16925;
  }
  }
  </code></pre>