Detailed introduction to session in ASP

Session object is used to store user information. Variables stored in the session object hold information about a single user and are available to all pages in an application.

Session Object

When you work with an application, you open it, make changes, and then close it. It's a lot like a conversation. The computer knows who you are. It knows when you open and close apps. But there's a problem on the Internet: Since HTTP addresses cannot persist state, the web server doesn't know who you are or what you do.

ASP solves this problem by creating a unique cookie for each user. The cookie is transferred to the client and contains information that identifies the user. This interface is called a Session object.

Session objects are used to store information about the user, or to change settings for a user's session. Variables stored in the session object hold information about a single user and are available to all pages in the application. The information stored in the session object is usually name, id, and parameters. The server creates a new Session for each new user and revokes the Session object when the session expires.

When does the Session start?

Session starts at:

*When a new user requests an ASP file, and the Global.asa file references the Session_OnStart subroutine;

<%
Session.Timeout=5
%>

<%
Session.Abandon
%>

<%
Session("username")="Donald Duck"
Session("age")=50
%>

<%If Session("screenres")="low" Then%> 
  This is the text version of the page
<%Else%> 
  This is the multimedia version of the page
<%End If%>

<%
If Session.Contents("age")<18 then   Session.Contents.Remove("sale")End If 
%>

<%
Session.Contents.RemoveAll()
%>

<%
Session("username")="Donald Duck"
Session("age")=50
dim i
For Each i in Session.Contents
  Response.Write(i & "<br />")
Next
%>

username
age

<%
dim i
dim j
j=Session.Contents.CountResponse.Write("Session variables: " & j)
For i=1 to j
  Response.Write(Session.Contents(i) & "<br />")
Next
%>

Session variables: 2
Donald Duck
50

<%
dim i
For Each i in Session.StaticObjects
  Response.Write(i & "<br />")
Next
%>