Checking a null value in Objective-C that has been returned from a JSON string

I have a JSON object that is coming from a webserver. The log is something like this: { "status":"success", "UserID":15, "Name":"John", "DisplayName":"John", "Surname":"Smith", "Email":"email", "Telephone":null, "FullAccount":"true" } Note the Telephone is coming in as null if the user doesn't enter one. When assigning this value to a NSString, in the NSLog it's coming out as <null> I am assigning