title: Error: "Unrecognized selector" when using addObjects: on an NSMutableArray
body: <p>When executing </p>
  
  <pre><code>[self.blockViews addObject:curBlockView];
  </code></pre>
  
  <p>I get an error </p>
  
  <blockquote>
    <p>2011-07-01 13:35:26.240 Block Breaker[42061:207] -[__NSArrayI addObject:]: unrecognized selector sent to instance 0x4e037a0</p>
  </blockquote>
  
  <p>I am pretty new to Objective-C. Is it something in my <code>init</code> method?</p>
  
  <pre><code>//
  //  GameEngine.h
  //  Block Breaker
  //
  //  Created by Chris Muench on 7/1/11.
  //  Copyright 2011 N/A. All rights reserved.
  //
  
  #import &lt;Foundation/Foundation.h&gt;
  
  
  @interface GameEngine : NSObject {
      NSMutableArray *blockViews;
      int numBlockRows;
      int score;
  }
  @property (nonatomic, copy) NSMutableArray *blockViews;
  @property int numBlockRows;
  @property int score;
  
  - (void) setup;
  - (void) setupBlocks;
  @end
  
  
  //
  //  GameEngine.m
  //  Block Breaker
  //
  //  Created by Chris Muench on 7/1/11.
  //  Copyright 2011 N/A. All rights reserved.
  //
  
  #import "GameEngine.h"
  #import "Block.h"
  #import "BlockView.h"
  
  
  @implementation GameEngine
  @synthesize blockViews;
  @synthesize numBlockRows;
  @synthesize score;
  
  - (id) init
  {
      if ((self = [super init])) 
      {
          self.blockViews = [[NSMutableArray alloc] init];
          self.numBlockRows = 2;
          self.score = 0;
      }
      return self;
  }
  
  - (void) setup
  {
      [self setupBlocks];
  }
  
  - (void) setupBlocks
  {
      float blockWidth = 10;
      float blockHeight = 10;
      float rowSpacing = 2;
      float colSpacing = 2;
      float currentX = 0;
      float currentY=10;
      float screenWidth = 200;
  
      for (int rowCounter=0;rowCounter&lt;self.numBlockRows;rowCounter++)
      {
  
          while(currentX &lt;=screenWidth)
          {
              Block *curBlock = [[Block alloc] initWithWidth:blockWidth height:blockHeight];
              BlockView *curBlockView = [[BlockView alloc] initWithFrame:CGRectMake(currentX, currentY, curBlock.width, curBlock.height)];
              curBlockView.block = curBlock;
  
              [self.blockViews addObject:curBlockView];           
              currentX+=blockWidth+colSpacing;
              [curBlock release];
              [curBlockView release];
          }
  
          currentX=0;
          currentY+=blockHeight+rowSpacing;
      }
  
  
  }
  
  @end
  </code></pre>