FBJS friends birthday oauth 2.0

Question

my FB.login(function ends with scope as it should:

}, {scope:'user_birthday,friends_birthday'});

after the user logs in the function permissionsTest() fires:

function permissionsTest(){
    FB.api('me/friends?fields=birthday', {fields:'birthday'}, function(response) { 
        alert(response.data[1]);
        });
}

But all the alert returns is: [object Object] when I am trying to see something like: 12/09/1983

How should this work?

see: graph.facebook.com/me/friends?fields=birthday

You can clearly see that there is an object called "data" holding an array of objects called "id" and "birthday"

My previous attempts:
response.data[1] returns [object Object]
response returns [object Object]
response.data[1].id returns undefined
response.data[1].birthday returns undefined
response.id returns undefined
response.birthday returns undefined

I can't seem to get it right and I feel I have exhausted the docs, stack and google.

Answer 1

Some of the friends birthdays may be null. Check out the response with the Facebook Graph API Explorer:

{
  "data": [
    {
      "birthday": "03/03", 
      "id": "997"
    }, 
    {
      "id": "998"
    },
    {
      "birthday": "05/06/1986", 
      "id": "999"
    }
]

This was returning data for me:

FB.api('me/friends?fields=birthday', {fields:'birthday'}, function(response) { 
  for (var i = 0; i < response.data.length; i++) {
    alert(response.data[i].birthday);
  }
});