Swift - It's an NSDictionary Extension in swift to replace all NSNull values with a blank string.
var changedItem : NSDictionary = itemPre as! NSDictionary // Here itemPre is dictionary which containes one or more NSNull Values.
changedItem = changedItem .dictionaryByReplacingNullsWithBlanks() // changedItem will contain no NSNull, all null object replaced by blank string.
before replacing changedItem:-
date = "2015-11-18";
time = "1:48 pm";
statusID = 2;
url = "<null>";
After replacing changedItem:-
date = "2015-11-18";
time = "1:48 pm";
statusID = 2;
url = ""; // null has been replaced by blank string