We get friends hiding you, why does it only display the last value from the loop?

Question

JavaScript

I get a list of friends from the user with id 33919072, then running through the loop, I get a list of friends from each of his friends and look for id 33919072 in it -> if I don’t find it, then I display the ID that was not found in the list id 33919072.
If there is a hopeless situation, how can you do it the right way...

var userId = 33919072;
var i = '';
var f = '';
var GetUserName = function () {
VK.api('friends.get', {'user_id' : userId}, function(data) { 
  for (i = 0, l = data.response.length; i < l; i++) { 
  var script = document.createElement('SCRIPT');
  script.src = "https://api.vk.com/method/friends.get?user_id="+ data.response[i] +"&v=5.50&callback=callbackFunc"; 
  document.getElementsByTagName("head")[0].appendChild(script); 
  f = data.response[i];
    }
  });	
  };	
function callbackFunc(result) { 
   if (result.response.items.indexOf(userId) === -1) {
    console.log(f);
  } 
}

The script successfully finds such people, but displays only the id of the last user in the console (duplicating it) prntscr.com/av0a5u
How to display the id of these users?
In js, I don’t spit at all, so I did something like that, don’t throw stones strongly .. But myself))