title: How to check if json object contains <null>?
body: <p>I am getting a <strong>Json</strong> from server by making a network request in my app.I am getting <code>&lt;null&gt;</code> value for some keys in <strong>Json</strong> object.My app gets crashed if this type of response is received.Please tell me how can i validate>?</p>
  
  <p>I have tried this but it does not work all time.</p>
  
  <pre><code> if(!(user_post.username==(id)[NSNull null]) )
  {
  
          user_post.username=[dict_user_info objectForKey:@"name"];
           if(user_post.username!=nil)
              {
  
                 ser_post.username=[dict_user_info objectForKey:@"name"];
  
               }
          else
                {
  
                  user_post.username=@"Username";
  
                }
  
  }
  </code></pre>