title: json and empty array
body: <p>I have the following json  :</p>
  
  <pre><code>{
     "users":
      [{
         "user": 
          {
          "user_id"  :"a11uhk22hsd3jbskj",
          "username" :"tom",
          "location" : null
          }
      }]
  }
  </code></pre>
  
  <p>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).<br>
  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 :  </p>
  
  <pre><code>"location" : null 
  "location" : []
  </code></pre>
  
  <p>Thanks in advance </p>