## Setup proxy for automatic downloads
http_proxy=http://proxy.domain.com:6050
export http_proxy

## First lets download this following repositories:
wget http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-3.noarch.rpm
wget http://rpms.famillecollet.com/el5.i386/remi-release-5-6.el5.remi.noarch.rpm

## repository file location: /etc/yum.repos.d/dag.repo

## Now lets install them:
rpm -Uvh remi-release-5*.rpm epel-release-5*.rpm

yum –-enablerepo=remi update php* mysql*

yum localinstall ffmpeg-0.4.9-28_r15845.el5.i386.rpm

Repos:
======
remi-release-5-6.el5.remi.noarch.rpm
epel-release-5-3.noarch.rpm
rpmforge-release-0.3.6-1.el5.rf.i386.rpm
livna-release.rpm

rgrep -n “<search string here>” <directory path>

SCRIPT

1. What are the differences between Get and post methods in form submitting, give the case where we can use get and we can use post methods?
2. Who is the father of PHP and explain the changes in PHP versions?
3. How can we submit a form without a submit button?
Sol: document.form.submit();
4. In how many ways we can retrieve the date in the result set of MySQL using PHP?
5. What is the difference between mysql_fetch_object and mysql_fetch_array?
6. What is the difference between $message and $$message?

7. How can we extract string ‘abc.com ‘from a string ‘http://info@abc.com’ using regular expression of PHP?
8. How can we create a database using PHP and MySQL?
Sol: bool mysql_create_db (string database_name [, resource link_identifier])

9. What are the differences between require and include, include once?
Sol: The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again.

10. Can we use include (”abc.PHP”) two times in a PHP page “makeit.PHP”?
11. What are the different tables present in MySQL, which type of table is generated when we are creating a table in the following syntax: create table employee(eno int(2),ename varchar(10)) ?
12. Functions in IMAP, POP3 AND LDAP?
13. How can I execute a PHP script using command line?
14. Suppose your Zend engine supports the mode Then how can u configure your PHP Zend engine to support mode ?
15. Shopping cart online validation i.e. how can we configure Paypal, etc.?
16. What is meant by nl2br()?
17. Draw the architecture of Zend engine?
18. What are the current versions of apache, PHP, and MySQL?
19. What are the reasons for selecting lamp (Linux, Apache, MySQL, PHP) instead of combination of other software programmers, servers and operating systems?
20. How can we encrypt and decrypt a data present in a MySQL table using MySQL?
Sol: md5()
21. How can we encrypt the username and password using PHP?
Sol: md5()
22. What are the features and advantages of object-oriented programming?
23. What are the differences between procedure-oriented languages and object-oriented languages?
24. What is the use of friend function?
25. What are the differences between public, private, protected, static, transient, final and volatile?
26. What are the different types of errors in PHP?
27. What is the functionality of the function strstr and stristr?
28. What are the differences between PHP 3 and PHP 4 and PHP 5?
29. How can we convert asp pages to PHP pages?
30. What is the functionality of the function htmlentities?
31. How can we get second of the current time using date function?
32. How can we convert the time zones using PHP?
33. What is meant by urlencode and urldocode?
34. What is the difference between the functions unlink and unset?
35. How can we register the variables into a session?
36. How can we get the properties (size, type, width, height) of an image using PHP image functions?
Sol: list($width, $height, $type, $attr) = getimagesize(“img/flag.jpg”);

37. How can we get the browser properties using PHP?
38. What is the maximum size of a file that can be uploaded using PHP and how can we change this?
Sol: post_max_size = 8M (Maximum size of POST data that PHP will accept.)
upload_max_filesize = 2M (Maximum allowed size for uploaded files.)

39. How can we increase the execution time of a PHP script?
Sol: void set_time_limit (int seconds). The default limit is 30 seconds or, if it exists, the max_execution_time value defined in the php.ini

40. How can we take a backup of a MySQL table and how can we restore it. ?
41. How can we optimize or increase the speed of a MySQL select query?
42. How many ways can we get the value of current session id?
43. How can we destroy the session, how can we unset the variable of a session?
44. How can we destroy the cookie?
45. How many ways we can pass the variable through the navigation between the pages?
46. What is the difference between ereg_replace() and eregi_replace()?
47. What are the different functions in sorting an array?
48. How can we know the count/number of elements of an array?
49. What is the PHP predefined variable that tells the types of images that PHP supports?
50. How can I know that a variable is a number or not using a JavaScript?
51. List out some tools through which we can draw E-R diagrams for MySQL.
52. How can I retrieve values from one database server and store them in other database server using PHP?
53. List out the predefined classes in PHP?
54. How can I make a script that can be bilanguage (supports English, German)?
55. What are the difference between abstract class and interface?
56. How can we send mail using JavaScript?

DATABASE

1. How can we repair a MySQL table?
2. What are the advantages of stored procedures, triggers, indexes?
3. What is the maximum length of a table name, database name, and fieldname in MySQL?
4. How many values can the SET function of MySQL take?
5. What are the other commands to know the structure of table using MySQL commands except explain command?

6. How many tables will create when we create table, what are they?
7. What is the purpose of the following files having extensions 1) .frm 2) .myd 3) .myi? What do these files contain?
8. What is maximum size of a database in MySQL?
9. Give the syntax of Grant and Revoke commands?
10. Explain Normalization concept?
11. How can we find the number of rows in a table using MySQL?
12. How can we find the number of rows in a result set using PHP?
13. How many ways we can we find the current date using MySQL?
14. What are the advantages and disadvantages of Cascading Style Sheets?
15. What type of inheritance that PHP supports?
16. How can increase the performance of MySQL select query?
17. The structure of table view buyers is as follows:

+—————-+————-+——+—–+———+—————-+
| Field | Type | Null | Key | Default | Extra |
+—————-+————-+——+—–+———+—————-+
| user_pri_id | int(15) | | PRI | NULL | auto_increment |
| userid | varchar(10) | YES | | NULL | |
+—————-+————-+——+—–+———+—————-+

the value of user_pri_id the last row 2345 then What will happen in the following conditions?

Condition1: Delete all the rows and insert another row then. What is the starting value for this auto incremented field user_pri_id ,
Condition2: Delete the last row(having the field value 2345) and insert another row then. What is the value for this auto incremented field user_pri_id
18. What are the advantages/disadvantages of MySQL and PHP?
19. What is the difference between GROUP BY and ORDER BY in Sql?
20. What is the difference between char and varchar data types?
21. What is the functionality of md5 function in PHP?
22. How can I load data from a text file into a table?
23. How can we know the number of days between two given dates using MySQL?
24. How can we know the number of days between two given dates using PHP?
25. How can we change the name of a column of a table?
26. How can we change the name and data type of a column of a table?
27. What are the differences between drop a table and truncate a table?
28. When you want to show some part of a text displayed on an HTML page in red font color, what different possibilities are there to do this? What are the advantages/disadvantages of these methods?
29. When viewing an HTML page in a Browser, the Browser often keeps this page in its cache. What can be possible advantages/disadvantages of page caching? How can you prevent caching of a certain page (please give several alternate solutions)?
30. What are the different methods of passing data or information between two calls of a web page? What are the advantages/disadvantages of these methods?
31. An Apache web server is running on a Linux system. Suddenly, the web server delivers the pages very slow. How could you find out possible reasons for that (when using system commands, please specify their names)?
32. What are the different ways to login to a remote server? Explain the means, advantages and disadvantages?
33. Please give a regular expression (preferably Perl/PREG style), which can be used to identify the URL from within a HTML link tag. Example: The regular expression should match the tag and give the URL (”http://www.yoursite.com /”) as a return result. Tags should also be matched if they contain other attributes than the HREF attribute.
34. A select query over a large table runs very slow because of the growing number of entries in that table. What different measures could be taken to improve speed?
35. A company wants to store their invoices in a database. They already have their customers and articles in that database. Both customer and article are each identified by an unique integer value. Please create the SQL statements for creating the necessary table(s) for storing the invoices in a MySQL database. An invoice should hold information like invoice number, customer, date, article(s) and quantity etc.
36. For the database from the previous question, please give an SQL query which returns the invoice number of all invoices which contain the article with the number “1234?. The query should be able to run under a MySQL 4.0 database.
37. How would you backup and restore a big MySQL database? What are the advantages of the approach which you have taken over the others?
38. Create a PHP web script with the following attributes: on start, three HTML form elements are shown: an string input field, a checkbox field, a dropdown/pull down list with 5 elements and a submit button. On submission, the form should be redisplayed (while remaining all options/inputs as the user has selected/entered them). Additionally, the selections/inputs of the user should be displayed in text. Please solve this without the use of any external libraries.
39. What is MIME?
40. What is PEAR in PHP?
41. How can I use the COM components in PHP?
42. How can I load the DLLs dynamically?
43. How many ways we can give the output to a browser?
44. How can we know that a session is started or not?
45. What is the default session time in PHP and how can I change it?
46. What changes I have to done in PHP.ini file for file uploading?
47. What are the differences between MySQL_fetch_array(), MySQL_fetch_object(), MySQL_fetch_row()?
48. How can I set a cron and how can i execute it in Unix, Linux, and windows?
49. Steps for the payment gateway processing?
50. How many ways I can register the variables into session?
51. Explain different types of errors in PHP (i.e. arguments in errorreporting function)?
52. How many ways I can redirect a PHP page?
53. List out different arguments in PHP header function?
54. What type of headers have to add in the mail function in which file a attached?
55. What is the difference between
56. What are the differences between PHP3 and PHP4 versions?
57. What are the differences between include() and include_once() functions?
58. Describe the importance of DABA BASE ABSTRACTION LAYERS in PHP and database connection?
59. Explain MySQL optimization?
60. What is the difference between using copy() and move() function in PHP file uploading?
61. What is the difference between Reply-to and Return-path in the headers of a mail function?
62. Explain about Type Juggling in PHP?
63. How can I get the only name of the current executing file?
64. How can I embed a java program in PHP file and what changes have to be done in PHP.ini file?
65. How can I find what type of images that the PHP version supports?

$ sed -n ‘/start string/’,'/end string/p’ database.sql > usertable.sql

The above command will extract the inner content from the SQL file between ‘start string’ and ‘end string’.

LOAD DATA LOCAL INFILE ‘path/to/csv/file’ INTO TABLE `tablename` FIELDS TERMINATED BY ‘;’ ENCLOSED BY ‘”‘ ESCAPED BY ‘\\’ LINES TERMINATED BY ‘\r\n’(`id`,`name`,`value`,`isactive`);

$ mysqldump -u root -p dbname > dump.sql

If you need to restore your database, you can do so like this:

$ mysql -u username -p dbname < dump.sql

=====================================================

<%@ Page Language=”C#” Debug=”true” %>
<%@ Import Namespace=”System.Data” %>
<%@ Import Namespace=”System.Data.SqlClient” %>
<%@ Import Namespace=”System.Configuration” %>

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>

<script runat=”server”>
public class Program
{
public int sqlInsert()
{
string connstr = ConfigurationManager.ConnectionStrings["demowebdb"].ConnectionString;
string query = “INSERT INTO employee(fname,lname,gender,createdate,isactive) VALUES(‘t”s’,'tt’,'M’,'”+ DateTime.Now +”‘,1)”;
SqlConnection dbconn = new SqlConnection(connstr);
dbconn.Open();
SqlCommand cmd = new SqlCommand(query, dbconn);
int numrows = cmd.ExecuteNonQuery();
dbconn.Close();
return numrows;
}
}
</script>

<html xmlns=”http://www.w3.org/1999/xhtml”>
<head runat=”server”>
<title>SQLConnection Page</title>
</head>
<body>
<form id=”form1″ runat=”server”>
<div>
<%
Program p = new Program();
Response.Write(p.sqlInsert());
%>
</div>
</form>
</body>
</html>

Constructor: A special method on a class or struct that initializes the objects of that type.

Destructor: A special method on a class or struct that prepares the instance for destruction by the system.

Field: A data member of a class or struct that is accessed directly.

Generics: Generics allow you to define a class and or method that are defined with a type Parameter. When client code instantiates the type, it specifies a particular type as an argument.

Property: A data member accessed by means of an accessor.

Refactoring: Reusing previously entered code.

Q. What is polymorphism?
Q. What are the difference between Abstruct class and Interface?
* An Interface cannot implement methods.
* An abstract class can implement methods.

* An Interface can only inherit from another Interface.
* An abstract class can inherit from a class and one or more interfaces.

* An Interface cannot contain fields.
* An abstract class can contain fields.

* An Interface can contain property definitions.
* An abstract class can implement a property.

* An Interface cannot contain constructors or destructors.
* An abstract class can contain constructors or destructors.

* An Interface can be inherited from by structures.
* An abstract class cannot be inherited from by structures.

* An Interface can support multiple inheritance.
* An abstract class cannot support multiple inheritance.

Q. What is WSDL?
ANS: WSDL stands for Web Services Description Language which is an XML document used to describe Web services and also used to locate Web services.

Q. Describe ASP.NET page lifecycle.
ANS:
Page request:
The page request occurs before the page life cycle begins. When the page is requested by a user, ASP.NET determines whether the page needs to be parsed and compiled (therefore beginning the life of a page), or whether a cached version of the page can be sent in response without running the page.

Start:
In the start step, page properties such as Request and Response are set. At this stage, the page also determines whether the request is a postback or a new request and sets the IsPostBack property. Additionally, during the start step, the page’s UICulture property is set.

Page initialization:
During page initialization, controls on the page are available and each control’s UniqueID property is set. Any themes are also applied to the page. If the current request is a postback, the postback data has not yet been loaded and control property values have not been restored to the values from view state.

Load:
During load, if the current request is a postback, control properties are loaded with information recovered from view state and control state.

Validation:
During validation, the Validate method of all validator controls is called, which sets the IsValid property of individual validator controls and of the page.

Postback event handling:
If the request is a postback, any event handlers are called.

Rendering:
Before rendering, view state is saved for the page and all controls. During the rendering phase, the page calls the Render method for each control, providing a text writer that writes its output to the OutputStream of the page’s Response property.

Unload:
Unload is called after the page has been fully rendered, sent to the client, and is ready to be discarded. At this point, page properties such as Response and Request are unloaded and any cleanup is performed.

PAGE EVENTS:
PreInit -> Init -> InitComplete -> PreLoad -> Load -> [Control events] -> LoadComplete -> PreRender -> SaveStateComplete -> Render -> Unload.

Q. What is sealed class? How is it different from private class?
Q. What are the difference between char and varchar?
ANS: The CHAR is a fixed-length character data type, the VARCHAR is a variable-length character data type. CHAR should be used for storing fix length character strings. String values will be space/blank padded before stored on disk. If this type is used to store variable length strings, it will waste a lot of disk space.

Q. What are cursor, view and trigger?
Cursors are special programming constructs that allow data to be manipulated on a row-by-row basis, similar to other structured programming languages. They are declared like a variable, and then move one record at a time using a loop for control. There are three types of cursors, DYNAMIC, STATIC, and KEYSET. There are also three types of locks for cursors, READ ONLY, SCROLL LOCKS, and OPTIMISTIC.
Benefit – Fetch more records at time for that purpose you can use Cursor.

A View is a logical construct in the database. You basically create a virtual table in the database with a pre-defined query. Any other query can use the view.

Triggers are a special PL/SQL construct similar to procedures. However, a procedure is executed explicitly from another block via a procedure call, while a trigger is executed implicitly whenever the triggering event happens. The triggering event is an INSERT, DELETE, or UPDATE command. The timing can be either BEFORE or AFTER. The trigger can be either row-level or statement-level, where the former fires once for each row affected by the triggering statement and the latter fires once for the whole statement.

Q. What are the difference between primary key and unique key?
*Primary key should not contain nulls but unique key can contains null values.
*There is only one Primary key for one table but there may be more than one
Unique Key in a table.

Q. What is indexing?
Indexes are database tools that increase the system’s ability to retrieve data by not scanning all of the data records in search of the desired record(s). Indexes can change the organization of data so that it is structured similarly to how it will be accessed for retrieval. The indexes are created on column(s) to help the database find data based upon the value(s) contained in those indexed column(s).
Index Drawbacks:
Indexes are a performance drag when the time comes to modify records. Any time a query modifies the data in a table the indexes on the data must change also. Achieving the right number of indexes will require testing and monitoring of your database to see where the best balance lies. Static systems, where databases are used heavily for reporting, can afford more indexes to support the read only queries. A database with a heavy number of transactions to modify data will need fewer indexes to allow for higher throughput. Indexes also use disk space. The exact size will depends on the number of records in the table as well as the number and size of the columns in the index. Generally this is not a major concern as disk space is easy to trade for better performance.

Q. How do you remove duplicate entries from a table?
ANS:
EMPID EMPNAME EMPSSN
———- ———- ———–
1 Jack 555-55-5555
2 Joe 555-56-5555
3 Fred 555-57-5555
4 Mike 555-58-5555
5 Cathy 555-59-5555
6 Lisa 555-70-5555
7 Jack 555-55-5555
8 Mike 555-58-5555
9 Cathy 555-59-5555
10 Lisa 555-70-5555
11 Lisa 555-70-5555

delete from employee
where (empid, empssn)
not in
( select min(empid), empssn
from employee group by empssn); => EMPID Unique.

delete from employee
where (rowid, empssn)
not in
(select min(rowid), empssn from employee group by empssn); => Duplicate records once again but this time the empids and empSSNs are the same.

Q. What is MDAC (Microsoft Data Access Components)?
ANS: ADO, ODBC and OLE DB

Q. Difference between Application and Session?
An application variable exists from when the application is first ‘run’ (The first time a page in the app is used) and exists until the application is stopped on the server, either through IIS or the actual machine being turned off or rebooted.
A session variable is created for the instance of the browser accessing the site and will only be available until that browser is closed or the session times out.

Q. Assemblies:
An assembly is a fundamental building block of any .NET Framework application. For example, when you build a simple C# application, Visual Studio creates an assembly in the form of a single portable executable (PE) file, specifically an EXE or DLL.

Assemblies contain metadata that describe their own internal version number and details of all the data and object types they contain. This is known as Assembly Manifest.

Assemblies have the following properties:

*Assemblies are implemented as .exe or .dll files.

*You can share an assembly between applications by putting it in the Global Assembly Cache.

*Assemblies must be strong-named before they can be included in the Global Assembly Cache.

*Assemblies are only loaded into memory if they are required.

*You can programmatically obtain information about an assembly by using reflection.

*You can use two versions of the same assembly in a single application.

A private assembly is an assembly that is deployed with an application and is available for the exclusive use of that application. That is, other applications do not share the private assembly. Private assemblies are one of the methods that can be used to create isolated applications.

A shared assembly is an assembly available for use by multiple applications on the computer.

Difference:
* A private assembly is not required to be signed, and publickeyToken is not required in the <assemblyIdentity> element of the assembly manifest.
* Private assemblies can be installed into the application’s folder using any installation technology. Private assemblies are not required to be installed using the Windows Installer.

Q. Five(5) new features added in ASP.NET 2.0.
1. Master Page
2. App_Code
3. App_Data
4. Themes and Skins
5. <%$ … %>
6. 64-Bit Support

2. What’s the difference between Response.Write() andResponse.Output.Write()?
Response.Output.Write() allows you to write formatted output.

3. What methods are fired during the page load?
Init() – when the page is instantiated
Load() – when the page is loaded into server memory
PreRender() – the brief moment before the page is displayed to the user as HTML
Unload() – when page finishes loading.

4. When during the page processing cycle is ViewState available?
After the Init() and before the Page_Load(), or OnLoad() for a control.

5. What namespace does the Web page belong in the .NET Framework class hierarchy?
System.Web.UI.Page

6. Where do you store the information about the user’s locale?
System.Web.UI.Page.Culture

7. What’s the difference between Codebehind=”MyCode.aspx.cs” andsrc=”MyCode.aspx.cs”?
CodeBehind is relevant to Visual Studio.NET only.

8. What’s a bubbled event?
When you have a complex control, like DataGrid, writing an event processing routine for each object (cell, button, row, etc.) is quite tedious. The controls can bubble up their eventhandlers, allowing the main DataGrid event handler to take care of its constituents.

9. Suppose you want a certain ASP.NET function executed on MouseOver for a certain button. Where do you add an event handler?
Add an OnMouseOver attribute to the button. Example: btnSubmit.Attributes.Add(“onmouseover”,”someClientCodeHere();”);

10. What data types do the RangeValidator control support?
Integer, String, and Date.

11. Explain the differences between Server-side and Client-side code?
Server-side code executes on the server. Client-side code executes in the client’s browser.

12. What type of code (server or client) is found in a Code-Behind class?
The answer is server-side code since code-behind is executed on the server. However, during the code-behind’s execution on the server, it can render client-side code such as JavaScript to be processed in the clients browser. But just to be clear, code-behind executes on the server, thus making it server-side code.

13. Should user input data validation occur server-side or client-side? Why?
All user input data validation should occur on the server at a minimum. Additionally, client-side validation can be performed where deemed appropriate and feasable to provide a richer, more responsive experience for the user.

14. What is the difference between Server.Transfer and Response.Redirect? Why would I choose one over the other?
Server.Transfer transfers page processing from one page directly to the next page without making a round-trip back to the client’s browser. This provides a faster response with a little less overhead on the server. Server.Transfer does not update the clients url history list or current url. Response.Redirect is used to redirect the user’s browser to another page or site. This performas a trip back to the client where the client’s browser is redirected to the new page. The user’s browser history list is updated to reflect the new address.

15. Can you explain the difference between an ADO.NET Dataset and an ADO Recordset?
Valid answers are:
· A DataSet can represent an entire relational database in memory, complete with tables, relations, and views.
· A DataSet is designed to work without any continuing connection to the original data source.
· Data in a DataSet is bulk-loaded, rather than being loaded on demand.
· There’s no concept of cursor types in a DataSet.
· DataSets have no current record pointer You can use For Each loops to move through the data.
· You can store many edits in a DataSet, and write them to the original data source in a single operation.
· Though the DataSet is universal, other objects in ADO.NET come in different versions for different data sources.

16. What is the Global.asax used for?
The Global.asax (including the Global.asax.cs file) is used to implement application and session level events.

17. What are the Application_Start and Session_Start subroutines used for?
This is where you can set the specific variables for the Application and Session objects.

18. Can you explain what inheritance is and an example of when you might use it?
When you want to inherit (use the functionality of) another class. Example: With a base class named Employee, a Manager class could be derived from the Employee base class.

19. Whats an assembly?
Assemblies are the building blocks of the .NET framework. Overview of assemblies from MSDN

20. Describe the difference between inline and code behind.
Inline code written along side the html in a page. Code-behind is code written in a separate file and referenced by the .aspx page.

21. Explain what a diffgram is, and a good use for one?
The DiffGram is one of the two XML formats that you can use to render DataSet object contents to XML. A good use is reading database data to an XML file to be sent to a Web Service.

22. Whats MSIL, and why should my developers need an appreciation of it if at all?
MSIL is the Microsoft Intermediate Language. All .NET compatible languages will get converted to MSIL. MSIL also allows the .NET Framework to JIT compile the assembly on the installed computer.

23. Which method do you invoke on the DataAdapter control to load your generated dataset with data?
The Fill() method.

24. Can you edit data in the Repeater control?
No, it just reads the information from its data source.

25. Which template must you provide, in order to display data in a Repeater control?
ItemTemplate.

26. How can you provide an alternating color scheme in a Repeater control?
Use the AlternatingItemTemplate.

27. What property must you set, and what method must you call in your code, in order to bind the data from a data source to the Repeater control?
You must set the DataSource property and call the DataBind method.

28. What base class do all Web Forms inherit from?
The Page class.

29. Name two properties common in every validation control?
ControlToValidate property and Text property.

30. Which property on a Combo Box do you set with a column name, prior to setting the DataSource, to display data in the combo box?
DataTextField property.

31. Which control would you use if you needed to make sure the values in two different controls matched?
CompareValidator control.

32. How many classes can a single .NET DLL contain?
It can contain many classes.

Web Service Questions

1. What is the transport protocol you use to call a Web service?
SOAP (Simple Object Access Protocol) is the preferred protocol.

2. True or False: A Web service can only be written in .NET?
False

3. What does WSDL stand for?
Web Services Description Language.

4. Where on the Internet would you look for Web services?

http://www.uddi.org

5. True or False: To test a Web service you must create a Windows application or Web application to consume this service?
False, the web service comes with a test page and it provides HTTP-GET method to test.

State Management Questions

1. What is ViewState?
ViewState allows the state of objects (serializable) to be stored in a hidden field on the page. ViewState is transported to the client and back to the server, and is not stored on the server or any other external source. ViewState is used the retain the state of server-side objects between postabacks.

2. What is the lifespan for items stored in ViewState?
Item stored in ViewState exist for the life of the current page. This includes postbacks (to the same page).

3. What does the “EnableViewState” property do? Why would I want it on or off?
It allows the page to save the users input on a form across postbacks. It saves the server-side values for a given control into ViewState, which is stored as a hidden value on the page before sending the page to the clients browser. When the page is posted back to the server the server control is recreated with the state stored in viewstate.

4. What are the different types of Session state management options available with ASP.NET?
ASP.NET provides In-Process and Out-of-Process state management. In-Process stores the session in memory on the web server. This requires the a “sticky-server” (or no load-balancing) so that the user is always reconnected to the same web server. Out-of-Process Session state management stores data in an external data source. The external data source may be either a SQL Server or a State Server service. Out-of-Process state management requires that all objects stored in session are serializable.

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>

<script runat=”server”>
class OuterClass
{
public class InnerClass
{
public void Display()
{
HttpContext.Current.Response.Write(“Hello World!”);
}
}
}
</script>

<html xmlns=”http://www.w3.org/1999/xhtml”>
<head runat=”server”>
<title>Nested Class Page</title>
</head>
<body>
<form id=”form1″ runat=”server”>
<div>
<%
OuterClass o = new OuterClass();
OuterClass.InnerClass i = new OuterClass.InnerClass();
//OuterClass.InnerClass.Display();//if Display is static method
i.Display();
%>
</div>
</form>
</body>
</html>