title: An Important Question About NSDictionaries
body: <p>I have an NSDictionary with NSStrings</p>
  
  <p>Some of the valueForKey:@"Key" have no entry so it's (null)</p>
  
  <pre><code>NSMutableString* addressDictionaryToString = [NSMutableString string];  // use mutable string!
  for (NSDictionary* item in address) {     // use fast enumeration!
          [addressDictionaryToString appendFormat:@"%@, %@, %@, %@",
           [item objectForKey:@"Street"],         
           [item objectForKey:@"City"],
           [item objectForKey:@"State"],
           [item objectForKey:@"ZIP"]
           ];
      NSLog(@"MutableString: %@", addressDictionaryToString);
  }
  </code></pre>
  
  <p>So I want to build an NSMutableString but filter out those keys that are null. Any ideas?</p>
  
  <p>UPDATE:::::</p>
  
  <p>Basically I want my resulting String to look like</p>
  
  <p>1 Infinite Loop, Cupertino, CA, 95014 (IF all fields are available)</p>
  
  <p>If Im missing the Street then</p>
  
  <p>Cupertino, CA, 95014</p>
  
  <p>If I'm missing the State then</p>
  
  <p>1 Infinite Loop, Cupertino, 95014</p>
  
  <p>If I only have the state then it should print</p>
  
  <p>CA</p>
  
  <p>(notice that there are no commas on the last element)</p>