Facebook friends-of-friends

Question

How can I get the Facebook ids of the current logged in user's second degree friends or friends-of-friends?

Sample sites that do the same behaviour are the following:

• vark.com
• thread.com

Answer 1

将朋友存储在一个数组中，然后自己进行相交。

Answer 2

Following daaku's answer, it's technically not possible to get the friends of every friend. It is a limitation in the API. (Probably to block abusers from sending much spam etc.)

However, I checked out thread.com and it seems that on this particular website you have to log in with your facebook account (username + password).

As you probably know, you can actually see all the friends of a friend in the facebook web interface (when you're viewing their profile in a browser)

Knowing that, this is how I think they do it:

• With an embedded browser in a background-application on their server, they log on to your facebook.
• they navigate through the friends of every friend
• they extract the necessary information (probably at least the username and id from this page)
• voila.

However, I think this violates the facebook TOS, and it's also not ethical: at no time should you ask a user for their facebook password.

Answer 3

It is not possible to get a listing of friends of friends. Although, given two Facebook user ids you can check if they are friends using: http://developers.facebook.com/docs/reference/fql/friend