title: Changing a boolean in an NSMutableArray
body: <p>So I'm trying to change all the booleans in an NSMutableArray that I made which I followed from <a href="https://stackoverflow.com/questions/628343/objective-c-boolean-array">here.</a></p>
  
  <p>i have:</p>
  
  <pre><code>@property (nonatomic, retain) NSMutableArray *isDinosaurTapped;
  </code></pre>
  
  <p>and synthesized:</p>
  
  <pre><code>@synthesize isDinosaurTapped;
  </code></pre>
  
  <p>and set up [EDITED to show isDinosaurTapped]:</p>
  
  <pre><code>NSMutableArray *newDinosaurTaps = [[NSMutableArray alloc] init];
      for( int i = 0; i &lt; [dinoSprites count]; i++ )
      {
          NSNumber *isTapped = [posPlist valueForKeyPath:[NSString stringWithFormat:@"Dinosaurs.Dinosaur_%i.isTapped", i]];
          [newDinosaurTaps addObject:isTapped];
      }
      self.isDinosaurTapped = [newDinosaurTaps copy];
  
  
      for( int i = 0; i &lt; [isDinosaurTapped count]; i++ )
      {
          [isDinosaurTapped replaceObjectAtIndex:i withObject:[NSNumber numberWithBool:NO]];
      }
  </code></pre>
  
  <p>When I build its fine, however when I actually build and run, I keep getting a SIGABRT: '-[__NSArrayI replaceObjectAtIndex:withObject:]: unrecognized selector sent to instance.</p>
  
  <p>Have I set the properties of the NSMutableArray incorrectly?  But according to <a href="https://stackoverflow.com/questions/4050007/objective-c-what-is-the-best-way-to-create-and-use-a-dynamic-boolean-array">this</a>, my properties should be ok.</p>
  
  <p>Any feedback is greatly appreciated! :D</p>