Question

This is an interview question asked a month ago….

Do session use cookies? If so,how do they do so?

Assume Session["UserId"]=1 how does this session variable uses cookies internally? If so, what will be the name of the cookie and what is the value of that cookie….

Answer 1

Whilst the data its self is stored on the server (or in SQL if configured that way), there needs to be a way to associate session data with specific users.

By default this is done with a cookie, but you can configure cookieless in which case the unique id is stored in the URL.

From Microsoft:

ASP maintains session state by providing the client with a unique key assigned to the user when the session begins. This key is stored in an HTTP cookie that the client sends to the server on each request. The server can then read the key from the cookie and re-inflate the server session state.

http://msdn.microsoft.com/en-us/library/ms972429.aspx