json and empty array

Question

I have the following json :

{    "users":     [{        "user":          {         "user_id"  :"a11uhk22hsd3jbskj",         "username" :"tom",         "location" : null         }     }] } 

I get this json in response to a request to an api. Looking at the doc for this api, location is supposed to be an array (containing geodata, latitude, longitude address etc).
Now the question is : there's an error in the json? I mean, location doesn't seems,to me, to be an array, or is possible to represent a null array in that way? and if yes what is the difference between :

"location" : null  "location" : [] 

Thanks in advance

Answer 1

"location" : null // this is not really an array it's a null object "location" : []   // this is an empty array 

It looks like this API returns null when there is no location defined - instead of returning an empty array, not too unusual really - but they should tell you if they're going to do this.

Answer 2

null is a legal value (and reserved word) in JSON, but some environments do not have a "NULL" object (as opposed to a NULL value) and hence cannot accurately represent the JSON null. So they will sometimes represent it as an empty array.

Whether null is a legal value in that particular element of that particular API is entirely up to the API designer.