Converting a Dictionary with a value of [NSNull null] to JSON

Question

I am trying to use this code:

NSDictionary *innerMessage 
      = @{@"nonce":[NSNumber numberWithInteger:nonce],
          @"payload":@{@"login": [NSNull null]}};

NSError * err;
NSData * innerMessageData = [NSJSONSerialization 
     dataWithJSONObject:innerMessage options:0  
     error:&err];

to create a JSON object with the following structure:

{
    "apikey": "e418f5b4a15608b78185540ef583b9fc",
    "signature": "FN6/9dnMfLh3wZj+cAFr82HcSvmwuniMQqUlRxSQ9WxRqFpYrjY2xlvDzLC5+qSZAHts8R7KR7HbjiI3SzVxHg==",
    "message":{
        "nonce": 12, 
        "payload": {
            "Login": {}
        }
    }
}

However, this is the actual result which I get:

{"nonce":1398350092512,"payload":{"login":null}}

• Why is [NSNull null] in my dictionary not being converted to {}?
• How would I need to change my code to get the correct JSON structure?

Thank you!

Answer 1

Change code to

NSDictionary *innerMessage = @{
                                   @"nonce":@12,
                                   @"payload":@{@"login": @{}}
                              };

NSError * err;
NSData * innerMessageData = [NSJSONSerialization 
     dataWithJSONObject:innerMessage options:0  
     error:&err];

This will create the desired response

{
    nonce = 12,
    payload =  {
        login = {}
    },
}