title: getting exception "index 0 beyond bounds for empty array"?
body: <p>i am getting start date and end date from user via date pickerview. when user scroll the pickerview in speed then it crashes there and gives me this exception. so whats the solution?</p>
  
  <p>[</p>
  
  <pre><code>NSMutableArray objectAtIndex:]: index 0 beyond bounds for empty array'
  *** Call stack at first throw:
  (
      0   CoreFoundation                      0x013fabe9 __exceptionPreprocess + 185
      1   libobjc.A.dylib                     0x0154f5c2 objc_exception_throw + 47
      2   CoreFoundation                      0x013f06e5 -[__NSArrayM objectAtIndex:] + 261
      3   iFeel                               0x0001e1b7 -[S7GraphView drawRect:] + 5714
      4   UIKit                               0x0047d6eb -[UIView(CALayerDelegate) drawLayer:inContext:] + 426
      5   QuartzCore                          0x01f6f9e9 -[CALayer drawInContext:] + 143
      6   QuartzCore                          0x01f6f5ef _ZL16backing_callbackP9CGContextPv + 85
      7   QuartzCore                          0x01f6edea CABackingStoreUpdate + 2246
      8   QuartzCore                          0x01f6e134 -[CALayer _display] + 1085
      9   QuartzCore                          0x01f6dbe4 CALayerDisplayIfNeeded + 231
      10  QuartzCore                          0x01f6038b _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 325
      11  QuartzCore                          0x01f600d0 _ZN2CA11Transaction6commitEv + 292
      12  QuartzCore                          0x01f907d5 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 99
      13  CoreFoundation                      0x013dbfbb __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 27
      14  CoreFoundation                      0x013710e7 __CFRunLoopDoObservers + 295
      15  CoreFoundation                      0x01339bd7 __CFRunLoopRun + 1575
      16  CoreFoundation                      0x01339240 CFRunLoopRunSpecific + 208
      17  CoreFoundation                      0x01339161 CFRunLoopRunInMode + 97
      18  GraphicsServices                    0x019de268 GSEventRunModal + 217
      19  GraphicsServices                    0x019de32d GSEventRun + 115
      20  UIKit                               0x0045442e UIApplicationMain + 1160
      21  iFeel                               0x00002990 main + 102
      22  iFeel                               0x00002921 start + 53
  )
  terminate called after throwing an instance of 'NSException'
  </code></pre>
  
  <p>the method @deepak and @ Grady Player are talking about is this:</p>
  
  <pre><code>-(void)getGraphicalData{
      NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
      //[NSThread sleepForTimeInterval:1];
  
      self.friendBL = [[FriendBL alloc] init];
      self.result = [self.friendBL  getGraphicalData1:txtStartTime.text andTodate:txtEndTime.text];
      if ([self.result isKindOfClass:[NSString class]]) {
          UIAlertView * friendListAlertView = [[UIAlertView alloc] initWithTitle:@"Friend List" message:(NSString*) self.result delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil];
          [friendListAlertView show];
          [friendListAlertView release];
      }
      else {
          self.reportList = (NSMutableArray*) self.result;
          NSLog(@"%d",[reportList count]);
      }
      [pool release];
  }
  </code></pre>
  
  <p>after selecting date i click on button to say done and this is the code</p>
  
  <pre><code>-(IBAction)doneBtn{
  
      [dateView setHidden:YES];
      NSLog(@"%@",[dateTimePicker date]);
      NSLocale *locale = [[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"] autorelease];
  
      NSDateFormatter *dateFormatter = [[NSDateFormatter alloc]init];
      [dateFormatter setDateStyle:NSDateFormatterBehaviorDefault];
  
      NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
      [dateFormat setDateFormat:@"MM/dd/yyyy hh:mm:ss"];
      dateFormat.locale = locale;
      if (tag) {
          txtEndTime.text=[dateFormat stringFromDate:[dateTimePicker date]];
          if (![self compareDates]) {
              txtStartTime.text=@"";
              txtEndTime.text=@"";
              UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Warning!" message:@"Date is not in valid" delegate:self cancelButtonTitle:@"ok" otherButtonTitles:nil];
              [alert show];
              [alert release];
          }
  
      }
      else {
          txtStartTime.text=[dateFormat stringFromDate:[dateTimePicker date]];
      }
      NSLog(@"%@",[dateFormat stringFromDate:[dateTimePicker date]]);
  
  
  
  }
  </code></pre>
  
  <p>but if i pick a the date slowly it do not crashes</p>