title: UITableView shows nothing
body: <p>When I run the application to show the UITableView, it turns out nothing. It will not run :</p>
  
  <pre><code>- (NSInteger)tableView:(UITableView *)tableView 
  numberOfRowsInSection:(NSInteger)section {} 
  </code></pre>
  
  <p>and </p>
  
  <pre><code>- (UITableViewCell *)tableView:(UITableView *)tableView 
  cellForRowAtIndexPath:(NSIndexPath *)indexPath {}
  </code></pre>
  
  <ol>
  <li>development environment is IOS SDK 6.1. / simulator version is 6.0.</li>
  <li>I used table view controller in storyboard.</li>
  <li><p>I created a class called "RetrieveDataFromDBTableVC" and set the table view controller's custom class to "RetrieveDataFromDBTableVC". 
  <img src="https://i.stack.imgur.com/t6jve.png" alt="enter image description here"></p></li>
  <li><p>I think the delegate and data source already set up for me, so I do not need to set again right? (The connection of delegate and datasource is Table View). </p></li>
  </ol>
  
  <p><img src="https://i.stack.imgur.com/4cUQH.png" alt="enter image description here"></p>
  
  <ol start="5">
  <li><p>In "RetrieveDataFromDBTableVC" class I defined like the following:</p>
  
  <pre><code>  - (void)viewDidLoad
    {
      [super viewDidLoad];
      [self retrieveData];
    }
  
    -(void)retrieveData
    {
        NSURL * url = [NSURL URLWithString:getDataURL];
        NSData * data = [NSData dataWithContentsOfURL:url];
  
        citiesArray = [[NSMutableArray alloc]init];
  
        // Assign data
        NSString * cID = @"aa";
        ...
  
        cities * myCity = [[cities alloc]initWithCityID:cID andCityID:cName andCityState:cState andCityPopulation:cPopulation andCityCountry:cCountry];
  
        // Add city object to our cities array
        [citiesArray addObject:myCity];
  
        // Create a myTableView outlet for this table view to reload data 
        // self.tableView is also correct right?
        [self.myTableView reloadData];
     }
  
     - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:    (NSInteger)section
     {
        // It will not run this function !!
        return [citiesArray count];
     }
  
     // It will not go into this function either !!
     - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    {
       // Set the identifier name in UITableViewCell also
       static NSString *CellIdentifier = @"cities";
       UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
  
       // Retrieve the current city object for use with this indexPath.row
      cities * currentCity = [citiesArray objectAtIndex:indexPath.row];
  
      cell.textLabel.text = currentCity.cityName;
  
      return cell;
    }
  </code></pre></li>
  </ol>
  
  <p>I think the connection is the problem, but I do not know how to figure that out. Thanks !!</p>