title: NSDictionaray dictionaryWithObjectsAndKeys adding NULL value
body: <p>I want to create a <a href="http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSDictionary_Class/Reference/Reference.html" rel="noreferrer">NSDictionary</a> with <a href="http://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSDictionary_Class/Reference/Reference.html#//apple_ref/occ/clm/NSDictionary/dictionaryWithObjectsAndKeys:" rel="noreferrer">+[NSDictionary dictionaryWithObjectsAndKeys:]</a>.  One of my keys has a string but the string can sometimes be <code>nil</code>.  If the string is <code>nil</code>, any other value key pairs I put afterward will be ignored because the list is prematurely terminated.  What is the standard way to deal with the possibility that there might be a value with <code>nil</code> in a <code>NSDictionary</code>?</p>