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

Programmer Question

Heya,

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

What is the correct way to check this value? It's preventing me from saving a NSDictionary.

I have tried using the conditions [myString length] and myString == nil and myString == NULL

Additionally where is the best place in the iOS documentation to read up on this?

Many thanks

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