C#

C# Interview Questions

This is a list of questions I have gathered from other
sources and created myself over a period of time from my
experience, many of which I felt where incomplete or simply
wrong. I have finally taken t time to go through each
he
question and correct them to the best of my ability. However,
please feel free to post feedback to challenge, improve, or
suggest new questions. I want to thank those of you that have
contributed quality questions and corrections thus far.

There are some question in this list that I do not consider to be
good questions for an interview. However, they do exist on
other lists available on the Internet so I felt compelled to keep
them easy access.

General Questions

1. Does C# support multiple-inheritance?
No.

2. Who is a protected class-level variable available
to?
It is available to any sub-class (a class inheriting this
class).

3. Are private class-level variables inherited?
Yes, but they are not accessible. Although they are not
visible or accessible via the class interface, they are
inherited.

4. Describe the accessibility modifier “protected
internal”.
It is available to class that are within the same
es
assembly and derived from the specified base class.

5. What’s the top .NET class that everything is
derived from?
System.Object.

6. What does the term immutable mean?
The data value may not be changed. Note: The
variable value may be changed, but the original
immutable data value was discarded and a new data
value was created in memory.

7. What’s the difference between System.String
and System.Text.StringBuilder classes?
System.String is immutable. System.StringBuilder was
designed with the purpose of having a mutable string
where a variety of operations can be performed.

8. What’s the advantage of using
System.Text.StringBuilder over System.String?
StringBuilder is more efficient in cases where there is a

large amount of string manipulation. Strings are
immutable, so each time a string is changed, a new
instance in memory is created.

9. Can you store multiple data types in
System.Array?
No.

10. What’s the difference between the
System.Array.CopyTo() and
System.Array.Clone()?
The Clone() method returns a new array (a shallow
copy) object containing all the elements in the original
array. The CopyTo() method copies the elements into
another existing array. Both perform a shallow copy. A
shallow copy means the contents (each array element)
contains references to the same object as the elements
in the original array. A deep copy (which neither of
these methods performs) would create a new instance
of each element's object, resulting in a different, yet
identacle object.

11. How can you sort the elements of the array in
descending order?
By calling Sort() and then Reverse() methods.

12. What’s the .NET collection class that allows an
element to be accessed using a unique key?
HashTable.

13. What class is underneath the SortedList class?
A sorted HashTable.

14. Will the finally block get executed if an exception
has not occurred?
Yes.

15. What’s the C# syntax to catch any possible
exception?
A catch block that catches the exception of type
System.Exception. You can also omit the parameter
data type in this case and just write catch {}.

16. Can multiple catch blocks be executed for a
single try statement?
No. Once the proper catch block processed, control is
transferred to the finally block (if there are any).

17. Explain the three services model commonly know
as a three-tier application.
Presentation (UI), Business (logic and underlying code)
and Data (from storage or other sources).

Class Questions

1. What is the syntax to inherit from a class in C#?
Place a colon and then the name of the base class.
Example: class MyNewClass : MyBaseClass

2. Can you prevent your class from being inherited
by another class?
Yes. The keyword “sealed” will prevent the class from
being inherited.

3. Can you allow a class to be inherited, but prevent
the method from being over-ridden?
Yes. Just leave the class public and make the method
sealed.

4. What’s an abstract class?
A class that cannot be instantiated. An abstract class is
a class that must be inherited and have the methods
overridden. An abstract class is essentially a blueprint
for a class without any implementation.

5. When do you absolutely have to declare a class
as abstract?
1. When the class itself is inherited from an abstract
class, but not all base abstract methods have been
overridden.
2. When at least one of the methods in the class is
abstract.

6. What is an interface class?
Interfaces, like classes, define a set of properties,
methods, and events. But unlike classes, in terfaces do
not provide implementation. They are implemented by
classes, and defined as separate entities from classes.

7. Why can’t you specify the accessibility modifier
for methods inside the interface?
They all must be public, and are therefore public by
default.

8. Can you inherit multiple interfaces?
Yes. .NET does support multiple interfaces.

9. What happens if you inherit multiple interfaces
and they have conflicting method names?
It’s up to you to implement the method inside your own
class, so implementation is left entirely up to you. This
might cause a problem on a higher-level scale if
similarly named methods from different interfaces
expect different data, but as far as compiler cares
you’re okay.
To Do: Investigate

10. What’s the difference between an interface and
abstract class?
In an interface class, all methods are abstract - there is
no implementation. In an abstract class some methods
can be concrete. In an interface class, no accessibility
modifiers are allowed. An abstract class may have
accessibility modifiers.

11. What is the difference between a Struct and a
Class?
Structs are value-type variables and are thus saved on
the stack, additional overhead but faster retrieval.
Another difference is that structs cannot inherit.

Method and Property Questions

1. What’s the implicit name of the parameter that
gets passed into the set method/property of a
class?
Value. The data type of the value parameter is defined
by whatever data type the property is declared as.

2. What does the keyword “virtual” declare for a
method or property?
The method or property can be overridden.

3. How is method overriding different from method
overloading?
When overriding a method, you change the behavior of
the method for the derived class. Overloading a
method simply involves having another method with the
same name within the class.

4. Can you declare an override method to be static
if the original method is not static?
No. The signature of the virtual method must remain
the same. (Note: Only the keyword virtual is changed
to keyword override)

5. What are the different ways a method can be
overloaded?
Different parameter data types, different number of
parameters, different order of parameters.

6. If a base class has a number of overloaded
constructors, and an inheriting class has a
number of overloaded constructors; can you
enforce a call from an inherited constructor to a
specific base constructor?
Yes, just place a colon, and then keyword base
(parameter list to invoke the appropriate constructor) in
the overloaded constructor definition inside the

inherited class.

Events and Delegates

1. What’s a delegate?
A delegate object encapsulates a reference to a
method.

2. What’s a multicast delegate?
A delegate that has multiple handlers assigned to it.
Each assigned handler (method) is called.

XML Documentation Questions

1. Is XML case-sensitive?
Yes.

2. What’s the difference between // comments, /*
*/ comments and /// comments?
Single-line comments, multi-line comments, and XML
documentation comments.

3. How do you generate documentation from the C#
file commented properly with a command-line
compiler?
Compile it with the /doc switch.

Debugging and Testing Questions

1. What debugging tools come with the .NET SDK?
1. CorDBG – command-line debugger. To use
CorDbg, you must compile the original C# file using t
he
/debug switch.
2. DbgCLR – graphic debugger. Visual Studio .NET
uses the DbgCLR.

2. What does assert() method do?
In debug compilation, assert takes in a Boolean
condition as a parameter, and shows the error dialog if
the condition is false. The program proceeds without
any interruption if the condition is true.

3. What’s the difference between the Debug class
and Trace class?
Documentation looks the same. Use Debug class for

debug builds, use Trace class for both debug and
release builds.

4. Why are there five tracing levels in
System.Diagnostics.TraceSwitcher?
The tracing dumps can be quite verbose. For
applications that are constantly running you run the risk
of overloading the machine and the hard drive. Five
levels range from None to Verbose, allowing you to
fine-tune the tracing activities.

5. Where is the output of TextWriterTraceListener
redirected?
To the Console or a text file depending on the
parameter passed to the constructor.

6. How do you debug an ASP.NET Web application?
Attach the aspnet_wp.exe process to the DbgClr
debugger.

7. What are three test cases you should go through
in unit testing?
1. Positive test cases (correct data, correct output).
2. Negative test cases (broken or missing data,
proper handling).
3. Exception test cases (exceptions are thrown and
caught properly).

8. Can you change the value of a variable while
debugging a C# application?
Yes. If you are debugging via Visual Studio.NET, just
go to Immediate window.

ADO.NET and Database Questions

1. What is the role of the DataReader class in
ADO.NET connections?
It returns a read-only, forward-only rowset from the
data source. A DataReader provides fast access when a
forward-only sequential read is needed.

2. What are advantages and disadvantages of
Microsoft-provided data provider classes in
ADO.NET?
SQLServer.NET data pr ovider is high-speed and robust,
but requires SQL Server license purchased from
Microsoft. OLE-DB.NET is universal for accessing other
sources, like Oracle, DB2, Micros Access and
oft
Informix. OLE-DB.NET is a .NET layer on top of the OLE
layer, so it’s not as fastest and efficient as
SqlServer.NET.

3. What is the wildcard character in SQL?
Let’s say you want to query database with LIKE for all
employees whose name starts with La. The wildcard
character is %, the proper query with LIKE would
involve ‘La%’.

4. Explain ACID rule of thumb for transactions.
A transaction must be:
1. Atomic - it is one unit of work and does not
dependent on previous and following transactions.
2. Consistent - data is either committed or roll
back, no “in-between” case where something has been
updated and something hasn’t.
3. Isolated - no transaction sees the intermediate
results of the current transaction).
4. Durable - the values persist if the data had been
committed even if the system crashes right after.

5. What connections does Microsoft SQL Server
support?
Windows Authentication (via Active Directory) and SQL
Server authentication (via Microsoft SQL Server
username and password).

6. Between Windows Authentication and SQL
Server Authentication, which one is trusted and
which one is untrusted?
Windows Authentication is trusted because the
username and password are checked with the Active
Directory, the SQL Server authentication is untrusted,
since SQL Server is the only verifier participating in the
transaction.

7. What does the Initial Catalog parameter define
in the connection string?
The database name to connect to.

8. What does the Dispose method do with the
connection object?
Deletes it from the memory.
To Do: answer better. The current answer is not
entirely correct.

9. What is a pre-requisite for connection pooling?
Multiple processes must agree that they will share the
same connection, where every parameter is the same,
including the security settings. The connection string
must be identical.

Assembly Questions

1. How is the DLL Hell problem solved in .NET?
Assembly versioning allows the application to specify

not only the library it needs to run (which was available
under Win32), but also the version of the assembly.

2. What are the ways to deploy an assembly?
An MSI installer, a CAB archive, and XCOPY command.

3. What is a satellite assembly?
When you write a multilingual or multi-cultural
application in .NET, and want to distribute the core
application separately from the localized modules, the
localized assemblies that modify the core application
are called satellite assemblies.

4. What namespaces are necessary to create a
localized application?
System.Globalization and Syst m.Resources.
e

5. What is the smallest unit of execution in .NET?
an Assembly.

6. When should you call the garbage collector in
.NET?
As a good rule, you should not call the garbage
collector. However, you could call the garbage collector
when you are done using a large object (or set of
objects) to force the garbage collector to dispose of
those very large objects from memory. However, this
is usually not a good practice.

7. How do you convert a value-type to a reference-
type?
Use Boxing.

8. What happens in memory when you Box and
Unbox a value-type?
Boxing converts a value-type to a reference-type, thus
storing the object on the heap. Unboxing converts a
reference-type to a value-type, thus storing the value
on the stack.

posted on Tuesday, March 16, 2004 8:09 AM

Feedback

# re: Interview Questions: C# 6/7/2004 7:25 AM
Mark Wagner
Add questions for:
- Global Assembly Cache (GAC)

- DataSet vs. DataReader
- Remoting

# re: Interview Questions: C# 6/22/2004 5:19 PM
Not sure about #34: quot;Why is it a bad idea to
Exceptions are there for a reason. It is so that you can
centralize your error handling code instead of having to
tediously monitor return codes and/or sprinkle error handling
code all over the place. A central location for managing errors is
much easier to maintain and test than having error code all
over the place.

Mark Wagner
A quick FYI, I did not write these questions myself. I found
them to be useful and wanted to keep a copy for myself since I
do hold technical interview from time to time. I have a link to
what I believe the source is.

As for question number 34, I do not agree completely with the
answer. Moreover, I don't think the answer is very complete or
clear.

I am currently putting together an Exception Handling Best
Practices document. This short post will not provide enough to
properly cover exception handling. I hope to post it soon, and
when I do it will be in my Developer Guidelines section just in
case you want to subscribe to that article category.

There are two primary exception throwing scenarios:
- Throwing a new exception (creating and throwing it)
- Re-Throwing an exception (an exception that has been caught
within a try/catch block)

THOWING (a new exception):
However, when it comes to quot;throwingquot; exceptions I have one
rule that is the most important of all.

Rule: Throw an exception only when the current
request/process simply can not progress due to incorrect,
insufficient data, or otherwise. If this code is in the UI an
exception should rarely be thrown since a user can usually be
notified of the error - such as an incorrect password. However,
for middle tier or non-UI code, throwing an exception is most
likely the correct response.

RE-THROWING (an existing exception):
The primary rule I have when quot;Re-Throwingquot; an exc
eption is:

Rule: Re-Throw an exception ONLY when you are adding value
to the exception process such as adding data to the exception

for debugging purposes. Otherwise, the try/catch should not
even be used since the exception will naturally propagate up
the call stack.

Eyal
Another good question
What is the difference between a Struct and a Class?

Structs are value-type variables and are thus saved on the
stack -> additional overhead but faster retrieval.

Another difference is that structs CANNOT inherit.

Manoj
Please put some more questions about oops here

manoj
Also put some more questions about Web Service, Assemblies,
events & delegates....

mm
What does the term immutable mean?

I believe it means to create a view of data that is not modifiable
and is temporary of data that is modifiable.

mm
What does the term immutable mean?

I believe it means to create a view of data that is not modifiable
and is temporary of data that is modifiable.

Vikas
Immutable means you can't change the currrent data, but if
you perform some operation on that data, a new copy is
created. The operation doesn't change the data itself. Like let's
say you have a string object having quot;helloquot; value. Now if you
say temp = temp + quot;new valuequot; a new o bject is created, and
values is saved in that. the temp object is immutable, and can't
be changed.

Did it help???

Raja A.S.
hi
The Question are Use ful but ,Question no 2

2. When you inherit a protected class-level variabl , who is it
e
available to?
Ans-Classes in the same namespace.

The above answer that is displayed in t page is wrong one
he
protected members can be acceable by all the derived class
irrespective of the Namespaces only protectedFriend or
protectedinternal will be accessed inside the namespace...

Murali
Hi,
Jc I need this important qns.
Regards
D.MURALI

# re: Interview Questions: C# 10/26/2004 12:59
PM pooja
Include the questions about deployment.

myhomevancouver
It's great.
One more question:
Difference between DataReader and DataAdapter / DataSet and
DataAdapter?

krishna
plz snd me more faq and meterial

Nyoti
Hi,

These questions are really very useful. Thank you very much for
that.
Multiple inheritance is not supported in C# but it can be
achieved using interfaces is fine. But can you please explain
why multiple inheritance of classes in not supported in C#?
Thanks in advance.

AM Tewodros Dori
Hi,
I found it to be a very useful resource. I appreciate you for
organizing the material in such a good order. It would be nice if
you could add some more questions in assemblies and
delegates and whenever possible to include some code excerpt.
Thanks a lot

prasad
wHAT IS THE DIFFERENCE BETWEEN THE CONSTRUCTORAND
DISTRUCTOR PLZ TELL

Azad
Hi,
Thanx a lot seding a useful chain of questions.Can u send me
some more of them

Bhupen parikh
These questions are really very useful. Thank you very much for
that but can u tell me why C# more used (preffered) than
VB.net ??

Mark Wagner
Hi Bhupen,

I began to answer your question and decided to post it here.
Good question.

http://blogs.crsw.com/mark/archive/2005/03/14/790.aspx

Ruchi Jain
These questions are really very helpful.I request you to add
more questions on event handling and delegates.

P.N.Balamurali
These Interview Questions is very useful for
every C# programmers but is not enough for us.
please send more interview question for us
this is useful one. Thank you............................

anshu

Hello thanks a lot for c# qiuestion can u send me another
question in c# and asp.net

Dev
so good. pls send me lot of interview question in C# and
asp.net .
thanks

P.V.Kameshwar
I was quite impressed by the questions, I request you to
provide indepth questions on wach and every topic which will be
much more useful for all

vnvskumar
Questions are good.Please keep add questions on events and
delegates,remoting and webservices.

vnvskumar
Questions are good.Please keep add questions on events and
delegates,remoting and webservices.

# re: Interview Questions: C#: Array.Copy vs
Array.Clone 4/18/2005 9:54 AM vtsr
Array.CopyTo does not make a deep copy. This can be easily
verified by running the following code.

public class MyClass
{
public static void Main()
{
Container[] containerArray = new Container[10];
for( int i=0; i < containerArray.Length; i++ ){
containerArray[i] = new Container( i );
}
Container[] containerArrayCopy = new Container[10];
containerArray.CopyTo( containerArrayCopy, 0 );

containerArrayCopy[2].V = 3;
Console.Write( quot;{0}, quot;, containerArray[i].V );
}
Console.WriteLine();
}

}

public class Container{
public int V;
public Container(int i ){
V = i;
}
}

Venu Madhav.Tsaliki

Mark Wagner
vstr

You are correct.

I am now trying to determine the difference between the
CopyTo and Clone - other than the starting index.

Thanks for pointing this out.

Mark

# re: Interview Questions: Dispose method
5/30/2005 1:38 AM Anand Thakur
Dispose places the connection back in the managed pool. so
that other object/class can use that connection for further use.

# sdf 6/1/2005 11:30 AM asdf
asdfasd

Ram Naresh Yadav Talluri M.C.A., M.S
( June 25th 2005 )
================ Holool India Written Test Paper (By.
Ram Naresh Yadav Talluri.(M.C.A .,
M.S))================

1. Use of Enable view state ? if turn off what happen ?
2. Response.write,server.transfer difference which one is used
when ?
3. server.transfer limitation ?
4. how can i kill user session ?
5. wild card character in sql ?
6. can aspx page contains two pager tags ?
7. can aspx page have multi language declarations ?
8. readonly syntax ?
9. which control is used to compare two controls?
10. two common propertys for any validation contro ?
11. what is an assembly ?
12. what is inheritancy where u required ?
13 polymorphism and advantage ?
14. what is the method while we are using adapter and
dataset ?
15. what are the things we generally declare in session_start ,
application_start ?
16. .net class library to find unique key?
17. can Array contains different datatypes ?
18. ACID properties ?
19. which tag i need to use manually to bind columns in a
datagrid ?
20. throw exception and rethrowing difference. ?
21. when garbage collector come into picture. ?
22. what is code behined and an aspx files a for?
re
23. how u maintain data while navigating o page to another
ne
24. --
25. --
----------Ram Naresh Yadav Talluri.(M.C.A .,
M.S)--------------------
yaduvancy@india.com

latha
What does the Dispose method do with the connection object?
The right answer for this question is:
The dispose method will release all the resources owned by the
object. And then it calls the dispose() of its parent class. This is
probagated through the base type hierarchy.

Tejas
questions are good.please continue the good work

jkyoutsey
Best definition for a delegate I've ever seen is a quot;type safe
function pointerquot;. That really cleared things up for me.

Majid
Array.CopyTo handles type casting automatically but Clone
needs explicit casting.

mamta
these questions are really helpfl while preparing 4 an interview.
could u plz tell me that why c# is preffered language for
asp.net?

# re: Interview Questions: C# 8/1/2005 1:36 AM T
V SURESH
good

# Interview questions on C# 8/2/2005 2:55 AM
Niranjan
Here few questions that I had faced for Symphony firm in
Bangalore...

1) Can we have private constructor? when can I use them?

2) what is an internal specifier? what happens internally when I
use access specifier Internal ?

3) DO we have inline function in C#? ohterwise what is
equivalent inline function in C#?

I would be greatful if somebody can give me wiht proper
justification for the above questions?

Thankx in advance...

Smita
Hi,

Question: 1) Can we have private constructor? when can I use
them?

Answer: private constructors can be used when u donot want
the class's object to be created. Since the constructor cannot be
accessed, an object of the class cannot be created. A possible
scenario would be , a class with sta methods.. which dont
tic
need object instance to be called.

anu
plz send some questions on threads and exceptional handling
too.

# Question number 9 in Classes 8/5/2005 7:15 AM
Shikher Bisaria
This question can be explained using Explicit interface
Implementation ..please look this up on msdn..they have a
pretty nifty explanation

Dan Masters
The answer to general question 1 is incorrect. The language
supports multiple interface inheritance though it doesn't support
multiple class inheritance.

sarah
Hi,
what are the meaning of copy constructor & distructor??

Thank you very much.

Fire Ozzy
Good collection... But seems to be basic..
Pls try to put some deep dive questions..

KS
Mark, could you please include some information on
system.threading class?

Sanket
Hello there,

Can someone explain when we inherit from HttpApplication to
create a class for Global.asax,
Why do we NOT have to override Application_Start or any other
event handler methods ??

Or, How is that eventhandler linked with the event?

Thanks
Sanket_Vaidya@hotmail.com

Tejas
Really superb site..

really ejoying while reading this site... nice one

best of luck go ahed ... :)

Adrian
Getting a bit petty here, but Hashtable has a lowercase t (i.e.
not HashTable).

Shougat Ahmed
This is very help to built my mobile enabled web site
http://www.b2bwebs ervice.com

Thanks.

Ram Naresh Talluri, Kiran Kumar Dopplapudi,
Ramara
1. Explain the differences between Server-side and Client-side
code?

ANS: Server side code will execute at server end all the
business logic will execute at server end where as client side
code will execute at client side at browser end.

2. What type of code (server or client) is found in a Code-
Behind class?

ANS : Server side.

3. Should validation (did t user enter a real date) occur
he
server-side or client-side? Why?

ANS : client side . there is no need to go to validate user input.
If it relates to data base validation we need to validate at server
side.

4. What does the quot;EnableViewStatequot; pr
operty do? Why would I
want it on or off?

ANS: IT keeps the data of the control during post backs.
if we turn off the values should not populate during server
round trip.

5. What is the difference between Server.Transfer and
Response.Redirect? Why would I choose one over the other?

ANS: Server.Trnasfer will prevent round trip. it will redirect
pages which or in the same directory. NO way to pass the query
strings . Thru http context we can able to get the previous page
control values.

Response.Redirect : There is a round trip to process the
request. We can redirect to any page external / internal other
than aspx. We can pass the query string thru which we can
manage sessions.

6. Can you give an example of when it would be appropriate to
use a web service as opposed to a non-serviced .NET

component

ANS : Web services are best suite for Hetrogenious
environment.
Remoting is best suite for Homogenious environment. The
systems that under CLR.

7. Let's say I have an existing application written using Visual
Studio 6 (VB 6, InterDev 6) and this application utilizes
Windows 2000 COM+ transaction services. How would you
approach migrating this
application to .NET

We need to have Wrapper to communicate COM components in
.net. and vis versa

CCW : Com Callable wrapper.
RCW : RUN time callable wrapper.

8. Can you explain the difference between an ADO.NET Dataset
and anADO Recordset?
ANS : DIsconnected architechure . Maintainace relation
schemas. MUtilple table grouping.
Connected one .
9. Can you give an example of what might be best suited to
place in the Application_Start and Session_Start subroutines?

ANS: APplication_start need for global variable whic are
h
available over the application.
Sesssion_Start : login dependent ( user dependent)

10. If I'm developing an application that must accomodate
multiple security levels though secure login and my ASP.NET
web appplication is
spanned across three web-servers (using round-robbin load
balancing)
what would be the best approach to maintain login-in state for
the
users?

ANS : Database Support.
or Thru state service.

11. What are ASP.NET Web Forms? How is this technology
different than what is available though ASP (1.0-3.0)?
ANS : ASP . Interprepter.. use the script engine.
ASP.Net Compiled.

12. How does VB.NET/C# achieve polymorphism?
ANS : Function overloading.
Operator overloading.
11. Can you explain what inheritance is and an example of
when you might use it?

ANS : Heridity.
Use the existing functionality along with its own properities.

13. How would you implement inheritance using VB.NET/C#?
ANS: Derived Class : Basecalss
VB.NEt : Derived Class Inherits Baseclass
14. Whats an assembly
ANS : A Basic unit of executable code >

Which contains : Manifest - Meta da ta
versioning , Calture , IL, Reference

15. Describe the difference between inline and code behind -
which is best in a loosely coupled solution

Tightly coupled - INLINE
ANS: inline function bind at compile time can write in aspx page
with in <% %> .

17. Explain what a diffgram is, and a good use for one

ANS : is an xml grammer. it talk about state of node in xml file.

18. Where would you use an iHTTPModule, and what ar the
e
limitations of any approach you might take in implementing one

ANS: Preprocessing before going to IIS.

20. What are the disadvantages of viewstate/what are the
benefits
ANS : IT can be hacked . page is size is heavy.

21 Describe session handling in a webfarm, how does it work
and what are the limits

ANS:
Session - mode
State sever
OUtprocess
sql

22. How would you get ASP.NET running in Apache web servers
- why would you even do this?

ANS: ---- Install Mod_AspDotNet
Add at the end of C:Program FilesApache
GroupApache2confhttpd.conf the following lines

23. Whats MSIL, and why should my developers need an
appreciation of it if at all?

ANS : Microsoft Intermeidate lanaguage. which is t out put
he
for all the .net supported languages after comiplation will
produce.
Appreciation for cross language support.

24. In what order do the events of an ASPX page execute. As a
developer is it important to undertsand these events?
ANS : INIT, PageLoad, Prerender , UNload.

25. Which method do you invoke on the DataAdapter control to
load your generated dataset with data?

Fill()

26. Can you edit data in the Repeater control?
NO

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

28. How can you provide an alternating color scheme in a
Repeatercontrol?

AlternateItemTemplate

29. What property must you set, and what method must you
call in your code, in order to bind the data from some data
source to the Repeatercontrol?

Datasource,
DataBind

30. What base class do all Web Forms inherit from?

System.Web.UI.Page

31. What method do you use to explicitly kill a user s session?

abondon()

32 How do you turn off cookies for one page in your site?
disablecookies.

33. Which two properties are on every validation control?
control to validate, error message
34. What tags do you need to add within the asp:datagrid tags
to bind
columns manually?
autogenerated columns is set to false
35. How do you create a permanent cookie?
Cooke = ne cookee().
cooke.adddate.

36. What tag do you use to add a hyperlink column to the
DataGrid?
hyper link column

37. What is the standard you use to wrap up a call to a Web
service
------------
38. Which method do you use to redirect the user to another
page without performing a round trip to the client?
server.transfer
39. What is the transport protocol you use to call a Web service
SOAP

http
40. True or False: A Web service can only be written in .NET
false
41. What does WSDL stand for? webservice discription
language. it is used to generate for proxy( server object)

42. What property do you have to set to tell the grid which page
to go to when using the Pager object?
Page Index.

43. Where on the Internet would you look for Web services?
UDDI
44. What tags do you need to add within the asp:datagrid tags
to bind columns manually.

Autogenerate columns

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

datatext
datavalue

46. How is a property designated as read-only?
get
47. Which control would you use if you needed to make sure
the values in two different controls matched?
compare filed validator

48. True or False: To test a Web service you must create a
windows application or Web application to consume this
service?
no
49. How many classes can a single .NET DLL con tain?

as many as u want..

Hemant Acharya
You put a nice comment on Private constructor.
But there is a pissed ...as constructor don't have access
modifier.
Please correct me ..If I am wrong.

Also can someone explain the type fidelity in .Net ?

Thanks.

Mark Wagner

Hermant, which question are your referring to?

# Interview Questions: Asp.net 10/3/2005 3:43
AM VENKATESHMOORTHY
is asp.net a platform independent language...if so please
explain in brief...thank you

chale astale
They very refreshing. Keep it up. I would like t questions to
he
be deeper so that we can grasp the technical part.

thank you

Mr_Confusion1
Hi,
When is CLR loaded in the memory? Is there only one instance
of CLR running when we are running multiple applicati ns?
o
How is CLR first loaded? How is an assembly loaded in CLR and
executed?
Mr_Confusion1

Manish Ahuja
Fist of all, Is ASP.NET a language? I believe it is a framework or
set of technologies that simplifies (relativity inferred here) the
job of creating .NET based web applications.

Mark Wagner
Hi Manish Ahuja,

You are correct is stating that ASP.NET is a technology that
provides a framework for developing .NET based web
applications.

Mark

Mark Wagner
VENKATESHMOORTHY,

ASP.NET is not a platform independen language. As was no ted
by Manish, ASP.NET is more of a technology that provides a
framework for building web applications. ASP.NET provides the
reources needed to dynamically deliver html content (pages) to
the end user. ASP.NET can leverage languages such as C#,
VB.NET, and javascript to help provide a reliable, high
perfofmance, and secure web application.

Mark

Manish Ahuja
Hi Mark,

Thanks! for clarification.

Manish

sunil
excellent , this site is really good..

kris
awesome help...thanks

Abdul Malik
good number of quality questions....

Vincent

Thanks for these useful questions

I got a question too

What is the base Class for Web Form?

chirurgia plastica
Thank you for this great article

srilatha
VENKATESHMOORTHY,

.net framework is independent because msil is independent can
be run anywhere.
but it is platform dependent because msil wil be converted to
native code which is understandable by windows.

# Interview Questions: C# 12/21/2005 9:03 PM
K.Senthil Kumar
Very nice colleciton...

PM Venu Madhav.Tsaliki

Venu Madhav.Tsaliki

Venu Madhav.Tsaliki

sneha
hello,
the Q list is really useful.
help on following questions is appreciated..
1. What is serialization, h ow it works in .NET?
2. What should one do to make class serializable?
3. What exactly is being s erialized when you perform
serialization?
4. scope in C#

Thanks
Sneha

Sarat Gollapudi
Hi,

Include some realtime development and deployment quesiotns.

Mukesh
Questions:
1)How Web service create Proxy Using WSDL.
2)How to call .NET Web s ervice from Java Appl. & Why ?
3)Is .NET really support fully OOP Concept?

I really found nice site to collect more lnowledge in .Net.
Please answers my Question

Thanks,
Mukesh

kk
hi the site is good but questions are of very basic level

Thirupathi Vangapalli

What is serialization, how it works in .NET?

The primary purpose of XML serialization in the .NET Framework
is to enable the conversion of XML documents and streams to
common language runtime objects and vice versa. Serialization
of XML to common language runtime objects enables one to
convert XML documents into a form where they are easier to
process using conventional programming languages. On the
other hand, serialization of objects to XML facilitates persisting
or transporting the state of such objects in an open, standards
compliant and platform agnostic manner.
--please refer to following article for more info
http://msdn.microsoft.com/library/default.asp?url=/library/en-
us/dnexxml/html/xml01202003.asp

shivaraj
Hi,

scope in C#

Simply, the scope of a type (a variable, a method, or a class) is
where you can use that type in your program. In other words,
the scope defines the area of the program where that type can
be accessible and referenced.

When you declare a variable inside a block of code (like a
method or an if statement structure), it will have a local scope,
and it will be called a local-variable. Local scope means that you
can't refer to that variable outside that block of code. Consider
the next example.

class Test
{
public void Test1()
{
int x = 0;
// some code goes here that uses the x variable
}

public void Test2()
{
Console.WriteLine(x);
}
}

Try to instantiate this class and you will get a compile-time
error inside method Test2() telling you that the name x doesn't
exist and that's because x is a local variable to the method
Test1() and method Test2() doesn't know anything about it. So
x has a local score to method Test1() only. Consider the next

example.

class Test
{

public void Test1()
{
int x = 0;

if(x == 0)
{

Console.WriteLine(quot;x equal t 0quot;);
o
}
}
}

Here, the method Test1() declares a local variable x (now x has
a local-scope to the method). Try to instance this class and
compile the code. It will work! Some beginners think that
because I said that x has a local scope to method Test1() it will
not be referenced from nested block (like the one we have here,
the If statement) but that's not true because any nested block
inside Test1() method can refer x because x is local for the
method and its all blocks of code.

shiv @@@

shivara.gk@gmail.com

shivaraj
shiv @@@@
shivaraj.gk@gmail.com

Shrikant
Thanks guys these questions really helped me a lot.
I am thankful to all of u !

Bye Take Care...........................

lavpal

Good Collection.. nice work..

Venu Madhav.Tsaliki

mathivanan
Realy Superb!!!!

Aaron Crandall
In Class Questions #4, it says quot;An abstract class is essentially a
blueprint for a class without any implementation.quot;

This is not true -- an abstract class can have an implementation
(this is what separates abstract classes from interfaces).

Neeraj Chaudhary
great job guys!

Could sm1 answer this plz?:

How can i create only one instance of class and thus doesn't
allow creating any more instances?

Mark Wagner
Neeraj,

What you are asking for is known as a Single ton class. Here is a
link that will cover what you are asking for.

http://www.c-
sharpcorner.com/Code/2003/Jan/Singlet
onPattern.asp

Mark Wagner

Dinesh
Hi, This is very usefull for me .
I Have one question can any one help me Please.....

Question : An Application has a single assembly file that has
different version how will you call the different version from
your application?

Shunmuga priyan
It is really superb....

# C# interview questions 2/20/2006 9:23 PM Alex
Barnett blog
Mark Wagner has collated some some interview questions (with
answers) you might be asked if you were...

nagesh
The above questions are good but this questions are not
suitable for experience persons. So please put the questions
with basics and give t questions for 2+ experience people.
he

Some person which don't pass 1 question
ad 1. There is multiple inheritance - but only for interfaces! I
answered yes on first interview and I don't pass it even I
answered that inheritance is multiple only for interfaces....

Anyway - questiona are good but sometimes better is to allow
someone write some code...

shweta
hi Really good work

I have a question tht when building that is while converting the
code to MSIL do we need the framework.

Pradeep
Very good questions and i will contribute some questions on C#
very soon.....

Keep going guys

vasu pavan kumar
hi friends, recently in an interview i faced a question
which is quot;why repeater control not dragged by mouse on web
page during design time?:
plz give me the answer to my mail id

: pavan.svr@gmail.com
i am waiting for ur response.

Andrew Polar
The job interview questions designed in presumption that
programmer faced problem when writing code and learned how
to solve it. There is a big difference in qualification of those who
learn from programming and those who learned from your site.
However, we can change the world and this site have right to
exist. Mu suggestion is make it collective. That means allow
everyone submit question and answer. Make group of experts
that decide if question and answer is good for the site and
publish it in sections not assorted. With that approach the site
will grow quickly, become popular and, in the future, kills C#
job interview questions, because everyone will answer them.
My regards.

Murali
hi,
Please any one mail me Dotnet interview questions

My mail id is muralidharan.rs@gmail.com

thanks and regards
murali

karabi adhikary
How can i write a validation script in a .cs file? or is it possible
to write java script code in a .cs file?

difference between arrays clone and copyto
methods
i still think the copyto method makes a deep copy and clone
method makes a shallow copy , if i am wrong correct me.

if i have a source array

arr1[0]=a
arr1[1]=b
arr1[2]=c

and a target array

arr2[0]=null
arr2[1]=null
arr2[2]=null
arr2[3]=null
arr2[4]=null

then if i make a copy using copyto method
and with starting index of 1

so my result will be

arr2[0]=null
arr2[1]=a
arr2[2]=b
arr2[3]=c
arr2[4]=null

now according to u if this is also a shallow copy 1,2,3 indexes of
target array(arr2[]) are pointing to the same memory location
as arr1[]'s.

Then arr2[0] , arr2[4] will be pointing to different memory
locations , which wont be in contigous memory locations of
arr2[1] or so.

Thats why i think copy makes a deep copy not shallow .
to

correct me if i am wrong

Manohar

Hi,

Thanks for proving nice faqs ,which are more useful to job
aspirants and developers
Regards,
Manohar

V.R.Patil
It's an great experiance, Good question and answers.
Thanks lot..

nilesh
Really good questions

more... Questions on .net Assembly

Sundeep Khatri
This is really helpful

E.Palani Raja
Hi,
Nice site covering most of the .Net related questions.

The following are some questions.

1. What is web garden?
2. What is object pooling?
3. Tell some thing about IIS isolation levels.

Regards

E.Palani Raja

Ravi
Can U some send some ASP.NET and C#.NET interview
question for my mail address ravishesham74@rediffmail.com
thanks

NarasimhaRao
Can any one let me know
What are design patterns in c#?

Gopalakrishnan
hi.. this things to know about c#

Ron
Hi,
I think you have a mistake in q 16:
You can have multiple catch statements, as you can see here:
http://www.c-
sharpcorner.com/Tutorials/ExceptionHandling101RVS.asp

Thanks,

Ron

Harpreet Sahani
Goood Collections of questions for interview...

SS

Great Collection........a lot of questions added in comments can
be added back to the initial list.

Veeru Patil
Hi,

This is very useful for us to know more things in the same
subject.. i am very happy with this.....pleas could you give us
e
some more question's with anwser that is helpful for us to reach
higher level of programming......Thank You ve much.
ry

.............................. God Bless you...............

Regards
V.R.Patil

nitin
please send me more c#.net interview questions

nitin
please send me more c#.net interview questions

thanushree
Thanks a lot please add more questions

thanushree
Thanks a lot please add more questions

Sony Syamala

Question: 1) Can we have private constructor? when can I use
them?

Yes, you can!!! This is used to mange the number of instances
of the object the users can create. This is also known as the
Singleton pattern. In singleton pattern you declare the
constructor as private and instantiate it from a static method
within you class. Pleas see the example below:
e

public sealed class MySingleton
{
static MySingleton instance = null;

private MySingleton()
{
}

public static MySinglet ClassInstance()
on
{
get
{
if (instance = = null)
{
instance = new MySingleton();
}
return instance;
}
}
}

Shashank
37. What is the standard you use to wrap up a call to a Web
service
Ans:SOAP

What's wrong with this code?
void fn(int n)
{
while(n != 0)
{
n >>= 1;
//do something
}
return;
}

Ans: What's wrong with this code?
void fn(int n)
{
while(n != 0)
{
n >>= 1;
//do something
}
return;
}

infinite looping if n is less than 0

# How to pass variable parameter list in c#?
5/2/2006 6:39 PM How to pass variable parameter
list in c#?
How to pass variable parameter list in c#?

# How to pass variable parameter list in c#?
5/2/2006 6:39 PM How to pass variable parameter
list in c#?
How to pass variable parameter list in c#?
using the params keyword.

# How will you implement the IDisposable
interface 5/2/2006 7:09 PM matt
class Test : IDisposable
{

public ~Test()
{
Dispose(false);
}
protected bool _disposed = false;

public void Dispose()
{
Dispose(true);
}

protected virtual void Dispose(bool disposing)
{
if(!_disposed)

{
_disposed = true;
if(disposing)
{
//do cleanup
}
}
}
}

Vinay
Hi...

I had written a function which contains 1 function with some
variables. I am calling tha function in my code many times &
t
everytime i am changing those values. So i want to that how
can i remove those earlier values . Can i use Dispose functions
& if yes how we can use that.

Thanks,
Vinay

Romrombus
Really this is good helpful for freshers.

kartheekkumar
Hello Everyone,
I would like to know how we can instantiate and connect to sql
server in windows authentication mode from visual studio and i
will be eagerly waiting for reply.
KartheekAnnavaram

Brian Ceccarelli
On General Question 15, a

catch (System.Exception)
{
}

does not catch every exception.

catch
{
}

does.

Some Microsoft code under-the-covers does not generate
System.Exceptions. When you make calls to native libraries, or
even call some SqlConnection methods, these calls can throw
an exception which is not inherited from System.Exception.

Satyanarayan Sahoo
I wanna get questionson VB.NET.

SEKAR
I WANT SQL QUERIES FOR INTERVIEW?. PLEASE SEND
DIFFERENT TYPE OF COMPLEX QUERIES ASKED IN INTERVIEW.

Amit
Hi All, The list of questions is good but does it matter? Think
over it, pick a topic and start questioning yourself, you will find
better questions to get answers on. The list is helpful, but only
if you find the answers. The answers are more important. I
speak with enough experience on this, I have interviewed many
people on C# being in the industry for more than 8 years.
STOP trying to get everything served on a platter......SURE
SHOT SERIES of questions?!! Lets discuss the answers friends,
the answers people are giving should be MODERATED........I
take that approach.....list out the questions, lets say 50
questions, and then start looking for answers.....SORRY WON'T
SERVE IT ALL TO YOU..........but for an example........see below
for WHAT I EXPECT HERE........

WHAT IS SERIALIZATION?
Serialization is the process of converting an object or a con-
nected graph of objects into a contiguous stream of bytes.
Deserialization is the process of converting a contiguous stream
of bytes back into its graph of connected objects. The ability to
convert objects to and from a byte stream is an incredibly
useful mechanism. Here are some examples:

• An application's state (object graph) can easily be saved in a
disk file or database and then restored the next time the
application is run. ASP.NET saves and restores session state by
way of serialization and deserialization.
• A set of objects can easily be copied to the system's clipboard
and then pasted into the same or another application. In fact,
Windows® Forms uses this procedure.
• A set of objects can be cloned and set aside as a backup while
a user manipulates the main set of objects.
• A set of objects can easily be sent over the network to a
process running on another machine. The Microsoft® .NET
Framework remoting architecture serializes and deserializes
objects that are marshaled by value.
Why would you want to use serialization? The two most
important reasons are
• to persist the state of an object to a storage medium so an
exact copy can be recreated at a later stage, and
• to send the object by value from one application domain to
another.

Sampada
Hi , Really this questions are good but I want questions for MCP
70-316

Dharmendra Kumar
Very good answer given by Amit. Thanks a lot.

Saw Myat Aung
-------------------------------------------------------------
# re: Interview Questions: C#: Array.Copy vs Array.Clone
4/18/2005 9:54 AM vtsr
Array.CopyTo does not make a deep copy. This can be easily
verified by running the following code.

public class MyClass
{
public static void Main()
{
Container[] containerArray = new Container[10];
containerArray[i] = new Container( i );
}

Container[] containerArrayCopy = new Container[10];
containerArray.CopyTo( containerArrayCopy, 0 );
containerArrayCopy[2].V = 3;
Console.Write( quot;{0}, quot;, containerArray[i].V );
}
Console.WriteLine();
}

}

public class Container{
public int V;
public Container(int i ){
V = i;
}
}
-------------------------------------------------------------
That's because Container is reference type. Array.Copyto
actually make new copy. But That newly generated copies only
hold the references not the actual value store in V.

# About Dispose mehod 5/25/2006 11:10 AM sivaji
Hi,
Dispose is the method, which we call us ually when we want the
object to be garbage collected. If u r calling Dispose() on inbuilt
classes like Form, It'll call a method Finalize() method, which
will usually used to cleanup any resources used with in the
form. With in this Finalize m ethod, we call the garbage collector
to recycle the memory. So, when u r using dispose method, it is
used to mark the object to Garbage Collectable. Calling the
Dispose dose't means, that object will b garbage collected
immidiately. GC will monitor the Managed memory for objects
Marked 4 garbage collectable. The recycling of memory depends
on when the GC will pay the visit.
Purely the Dispose method is not used for reseting the values in
the object. It is used to mark the Object to b collected by the
GC
thanx
sivaji

sreekumar
Great questions and comments guys...good team work ..keep
going

Anoop

I have a Question that was asked once..

Does any one know When all can the session state data be
retirieved. the choices I got were

1) during init
2) during prerender
and 3) during load event..

does any know abt it..

# Session State 6/2/2006 10:43 AM sivaji
Mr Anoop,
I believe, page init event will occur, when the request will b
handled by the worker process on server. Page_init is the first
event which will instantiate the page. Here itself u can get the
session state data if it is the first time request to the server.
The pre-render is the one of the stage in the page life cycle
where the page content will be converted to the browser
specific. The server can get the information about the browser
which made the request. Rendering means placing the controls
on the browser. Page_Pre-render event will fire just before the
page_render event. B4 the page render page load event fire.
...sivaji

# Session State 6/2/2006 10:44 AM sivaji
Mr Anoop,
I believe, page init event will occur, when the request will b
handled by the worker process on server. Page_init is the first
event which will fire when the page is instanciated. Here itself u
can get the session state data if it is the first time request to
the server. The pre-render is the one of the stage in the page
life cycle where the page content will be converted to the
browser specific. The server can get the information about the
browser which made the request. Rendering means placing the
controls on the browser. Page_Pre-render event will fire just
before the page_render event. B4 the page render page load
event fire.
...sivaji

Mark Wagner
Anoop,

Refer to this article. This provides an excellent overview of the
page events. Keep in mind this is specific to .NET 1.1. I expect
.NET 2.0 has additional events.

http://blogs.crsw.com/mark/articles/471.aspx

-Mark

# Excellent Collection 6/4/2006 1:19 AM Akash
Really a nice collection.

Harpreet Sahani
All the Questions and Answers r really good ......

Rupesh sharma
metadata consists of version information(4 values separeted by
3 dots) i.e major, minor, build and revision please explain the
meaning of these 4 values.

Rupesh sharma (S/W Devlpr. NIIT Ltd. Gurgaon)
can a com client early bind to an ms.net component? If yes how
can it be done?

Developer
In regards to quot;What does the Dispose method do with the
connection object?quot;, the Dispose() method will also close the
connection.

Panku
1). If we declare a class as a private class can we inherit that
class?

2). Can a declare public variables in a private class?If yes then

can we access those variables?

uXuf
What’s the .NET collection class that allows an element to be
accessed using a unique key?
HashTable.

I believe Dictionary is another class in framework 2.0 that gives
the same functionality.

Great work btw!

Narendra Krishna. T
ThanX alot for giving the list of questions. And It's a nice
gathering also.

Cheeers !

David Kim
Can static void Main() have any member functions(subroutines)
instead of class?

RAM NARESH YADAV TALLURI.
C#, ASP.NET, ADO.NET, XML:

? How many types of JIT compilers are available?
[Rama Naresh Talluri]
There are Two types of JIT compilers.
? standard JIT compiler.
? EconoJIT compiler.

? What are the different types of assemblies – name them?
Private
Public/Shared
Satellite assembly

? What is GAC? What are the steps to be taken to pick up the

latest version from GAC?
This Global Assembly Cache(GAC) stores .NET assemblies to be
shared by several applications on that computer.

publisher policy file is the configuration file to redirect to
different version

1. Create the publisher Policy assembly using the assembly
linker
2. Add the publisher policy assembly to the GAC using GACutil
tool
Gacutil /i
3. During runtime CLR is looking into the publisher policy file
and redirect the application to bind with new version assembly
as specified inside the publisher policy.

? How do we use different versions of private assemblies in
same application without re-build?
In Asseblyinfo file need specify assembly version.
assembly: AssemblyVersion

? Different methods of using a legacy COM component in .NET
framework?

1. TLBIMP to create an Assembly from a COM component
2. Reference a COM component directly from .NET Editor

? How do you implement SSL?

1. create certificate request
[
=>Right click on the website (VD)
=>Click Directory Security Tab and click Server Certificate
=> Type name of certificate , Organizatio name , server name
n
location info,
=> Type the path need to save certificate information Submit
certificate request.
]

2.Submit Certificate request.
[
=> Browse http://WebServerName/CertSrv/

=> select Request a Certificate and click Next
=> select Advanced Request and click Next
=> select Submit a Certificate Request using a Base64 and click
Next
=> open the request document quot;Create a certificate requestquot;
section
=> Copy the contents of the document
=> Paste the contents of the document into the Web form's
Base64 Encoded Certificate Request text box
=> Under Certificate Template, select Web Server or User, and
then click Submit
]

? Is it possible to debug java-script in .NET IDE? If yes, h
ow?

Yes. Write debugger statement to stop the cursor for debugging
.

? How do you create a webservice proxy without .NET IDE and
how do you test it?
wsdl utility we can test by consuming our service either
windows / web applicati no

? How to debug an assembly which is on Server?

[assembly: AssemblyDescription(quot;Debugquot;)]

? How many ways can we maintain the state of a page?

1.Client Side [ Query string, hidden variables, view
state,cookies]
2.Server side [application , session, database]

? How do we Generate and compile source code dynamically?

.Net provides powerful access to the IL code generation process
through the System.CodeDom.Compiler and Microsoft.CSharp
and Microsoft.VisualBasic namespaces. In these namespaces we
can find the tools that allow us to compile an assembly either to
disk or into memory. We can also need the Reflection
namespace as it contains the tools to invoke an object and its
methods once we have compiled the object.

? How to pass server control values from one form to another
using in-line code?
Server.Transfer

? How to make a webservice call asynchronous?

//Create a new instance of the Web Service Class
localhost.Service1 service = new
MyWebServiceApp.localh ost.Service1();
//Make the asynchronous Web Service call and call Writ
eHello
service.BeginHelloWorld(new System.AsyncCallback
(WriteHello), service);

private void WriteHello(System.IAsyncResult oR es)
{
//End the call
localhost.Service1 service =
(MyWebServiceApp.localh ost.Service1) oRes.AsyncState;
//Write the call result to a MessageBox
MessageBox.Show(service.EndHelloWorld(oRes));
}

? How to invoke a webservice using javascript?

<script language =”javascript”>
Function init()
{
Service.useservice(“/services/test.asmx?WSDL”, “MyTest”);
Var iCallID;
iCallID = service.MyTest.callService(“add”,1,2);
}

</script>

<body onload =”init()”>
<div id =”test” style =”behaviour:url(webservice.htc)”></div>
</body>

? List out all the possible ways of maintaining the state of a
session.
InProc
OutProc [State server, sql]

? What is the use of multicast delegate?
A multicast delegate can call more than one method.

? What is the purpose of a private constructor?
Prevent the creation of instance for a class

? Differentiate Dispose and Finalize.
Finalize is called by th Garbage Collector, and the state of
e
manage objects cannot be guaranteed, so we can not reference
them. Also, we cannot determine when the GC will run, and
which objects it will Finalize.

Dispose is called by the programmer, and is used to dispose of
managed and unmanaged objects. Within we dispose method,
we release all of our resources and call GC.SuppressFinalize as
we have done the work of the GC.

? What is the purpose of Singleton pattern?

Singleton pattern is used to make sure that only one instance of
a given class exists.

? Difference between structure and class.

Structures are value types;

classes are reference types.

Structures use stack allocation;
classes use heap allocation.

All structure elements are Public by default;
class variables and constants are Private by default, while other
class members are Public by default.

Structure elements cannot be declared as Protected; class
members can.

Structure variable declarations cannot specify initializers or
initial sizes for arrays; class variable declarations can.

Structures implicitly inherit from the System.ValueType class
and cannot inherit from any other type;

classes can inherit from any class or classes other than
System.ValueType.

Structures are not inheritable; classes are.

Structures are never terminated, so the common language
runtime (CLR) never calls the Finalize method on any structure;
classes are terminated by the garbage collector (GC), which
calls Finalize on a

class when it detects there are no active references remaining.

? Difference between DOM and SAX parser.


DOM Approach is useful for small documents in which the
program needs to process a large portion of the document.

SAX approach is useful for large documents in which the
program only needs to process a small portion of the document

SAX parsers generally requires more code than the DOM
interface.
Unless we build a DOM style tree from our application's internal
representation for the data, we can't as easily write the XML file
back to disk.

The DOM tree is not constructed, so there are potentially less
memory allocation.

If we convert the data in the DOM tree to another format, the
SAX API may help to remove the intermediate step

If we do not need all the XML data in memory, the SAX API
allows us to process the data as it is parsed

? Under what circumstances do you use DOM parser and SAX
parser

DOM Approach is useful for small documents in which the
program needs to process a large portion of the document.

SAX approach is useful for large documents in which the
program only needs to process a small portion of the document

If we do not need all the XML data in memory, the SAX API
allows us to process the data as it is parsed

? What is a well-formed XML and is the purpose of Diffgram?

A textual object is a well-formed XML document if it satisfies all
the following points
1. Taken as a whole, it m atches the production labeled
document.
2. It meets all the well-formedness constraints given in this
specification.
3. Each of the parsed entities which is referenced directly or
indirectly within the document is well-formed.

The purpose of Diffgram is the Ability to pass parameters. It
contains the tags that specify the original and new state of data

? Differentiate between legacy ADO recordset and .NET dataset.

What are typed datasets.
Recordset provides data one row at a time.
Connection is open .
Dataset is a data structure which represents the complete table
data at same time.
Dataset is just a data store and manipulation is done through
DataAdapters in .NET
Typed DataSets generate classes that expose each object the in
the DataSet in Type-saf manner. It will raise error at compile
e
time if any mismatch of column data type.

sai
Thankyou very much for the C# interview questions

Regards,
sai

ramya
Hi pls post me the .Net(C# and ASP.Net ) and SQL Server
interview questions with answers to my mail id which is
mailramya06@yahoo.com

Thank u so much.

yosuf
yeah this materila is good,but its not sufficient.if u add little
more to it,its better.anyone pls post me the .Net(C# and
ASP.Net ) and SQL Server interview questions with answers to
my mail id which is yusuf23in@rediffmail.c om

Venu Madhav.Tsaliki

Vijay
I have two independent classes like class A and Cla B so i
ss
want to use methods of Class A and Class B in Class C how do i
do. Condition is that Class A or Class B or not inherited each
other or not Suppose to use interfaces

Ganesan T
what is the difference between wcf and normal web service
calls?

Vivek Manohar Mani
Thankyou very much for the C# interview questions . This is
very helpfull for us.

Regards,
Vivek Manohar Mani

Sweeny
Very nice collection of interview questions and subsequent
discussions.

It'll be good if we all put questions for experienced (4-5 yrs)
people as well

Kaiser
What is a value type and a reference type? How to convert one
to another using Boxing?

Kaiser
What is a value type and a reference type? How to convert one
to another using Boxing?

Kaiser
What is reflection? Can you give me some examples of
reflection?

pankaj kumar singh MCA from Alagappa Univ.
very good question

Veena Prabhu
Please send some ASP.NET and C#.NET interview question on
my mail address veeprabhu@gmail.com

thanks.

subbu
I am preparing for the interview. Thanks a lot f the given
or
bunch of questions. Its helps me a lot. Thank you very much.

Regards,
Subbu

samir
nice collection and gr8 enthusiasm by all of those who have
contributed to make this richer.

Guru
Can you please send C#, ASP.NET, VB.NET and SQL Server
interview questions to my vguruprasath@yahoo.com ID. I've
been preparing for interview

Many Thanks,
Guru

Manish Singh
Can one pls send me some interview question on asp.net at
singhpmanish@yahoo.com.

Thnaks & Regards
Manish

Harika
Friends,

Can you send me some C#.net. ASP.net adn VB.net questions
to my email vennar_2005@yahoo.com

Thank you very much.

Harika

Ravi chandra
These are fine

Raji Chinnam

Hello Guys,

here are some other interview questions.

1. Explain about Normalization?
2. What is the difference between union & union all?
3. What kind of transactions can handled?
4. temporay tables use & how we can manage?

5. perfomance tuning steps?
6. Difference btn method overload / override?
7. When Garbage collector come into picture?
8. Difference btn refernce & value types?
9. boxing / unboxing in ASP.NET
10. assemblies
11. What manifest file contains?
12. MSIL
13. JIT
14. clas vs module
15. dataadapter
16. dataset
17. ado.net objects
18. difference btn and, and also
19. dataset.copy & dataset.clone
20. code access security
21. finalization
22. strogn type dataset

Raji Chinnam

Rama
What is the difference between Method Overriding and Method
Hiding in C#?

Praj
This is good. Can u please send me interview questions on c#,
.net, sql server and on xml. My email address is
prajshah@yahoo.com

Casey Gum
On the classes questsion , no. 9:

You can do explicit implementation if you need different
behavior.

public class Class1 : IFoo, IFoo2, IFoo3 {

public void TheMethod() {Console.Write(quot;1quot;);}
void IFoo.TheMethod() {Console.Write(quot;2quot;);}
void IFoo2.TheMethod() {Console.Write(quot;3quot;);}

}

Class1 myClass = new Class1();
myClass.TheMethod(); // writes out quot;1quot;;
((IFoo) myClass).TheMethod(); // writes out quot;2quot;;
((IFoo2) myClass).TheMethod(); // writes out quot;3quot;;
((IFoo3) myClass).TheMethod(); // writes out quot;1quot;;

shubhangi
i like this qu. & ans. which ar more helpfull in interview.
e

I would be greatfull to you if u send me more que.& ans.
related to ASP.NET,VB.NET,SQL SERVER,ADO.NET.....

shubhangi
e

related to ASP.NET,VB.NET,SQL SERVER,ADO.NET.....

chaukat anna
Gr8

Rupali
Hello sir,

Really ur ques. are very helpfull for me
thanks
Rupali

Surinder
Gud one...

satish chandra pandey
e
related to ASP.NET,C#,SQL SERVER,ADO.NET.. ...

Inferano
Hi ,
I wanted to know:
What can I do (or add) to a Page directive in .NET so that the
page is Pre-Complied?

What is the advantage /disadvantage of performing pre-
compilation?

Thanks

Ratnam
Hi,

Its realy useful for me, Tq.
Also i need some questions about release and debug.

TQ.

# Marker Interface (empty interface) 9/5/2006
10:53 PM Kalirajan
tell me the purpose of marker interface (empty interface) -
explain

praveen
very good what is the use of clone() method

Pankaj Singh
Interview que in C#.

Oleg Safronov
I am afraid the answer to the 4th question is wrong.

4. Describe the accessibility modifier “protected internal”.

It is available to class that are within the same assembly and
es
derived from the specified base class. - THIS IS WRONG.

The correct statement is:
It is available to class that are within the same assembly OR
es
derived from the specified base class.

(msdn states as following: Access is limit to the current
ed
assembly or types derived from the containing class.)

Please see C# Reference for details.

Oleg Safronov
The answer to the 9th question is also incorrect.

> Can you store multiple data types in System.Array?
> No.

Here you're sample code cutting:
=================================
Class1() {}
Class2() {}

Class3()
{
void main()
{
System.Array arr = new object[3];

arr.SetValue( new Class1(), 0 );
}
}

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

Since Class1, Class2 and Class3 are different datatypes the
right answer to the question is YES.

Rahul Sharma
Thanks Mark for such a Good collection of questions.

v.suresh
interview qustions are very good add some oop concepts

sheik
hi this is very use full. but i need more one word questions.

Yogesh
Nice Collection !!!!!

Bharathi Gurumoorthi
Very useful site i've seen so far.Please update this site,then
only we can able to update ourself in this language.

pavan kumar
this is god but a still to be added and a seperate page is need
for the questions and for the user feedback

and any plz forward me .new interview questions

Ramesh M
--> Overriding vs Overloading

--> ASP.Net page lifecycle

--> What is first event of Datagrid for binding the data.

--> What is itemcreated and itemdatabound

--> What is Postback

--> What is multi file Assembly.

--> How many assemblies u will get after compiling a solution
of some projects.

--> How the iis server processes a client request.

--> What are the contents of an assembly.

--> What is delay signing.

--> AppDomain vs HttpApplicationObject

Jaineesh
Questions are good but besides can you send me good more
questions on C# or asp.net on my mail address
jaineeshthakur@hotmail.com.

Thanx

Parth
Hey Friends,

As i m preparing for interview, please send me C#,ASP.NET and
VB.NET questions with ANSWERS on parthin06@yahoo.com
email address asap.

Thanking u in advance

Regards

Parth

Andrei Marculescu
For question no 9, I think your answer is wrong.

An array can contain objects of different types, but all these
object must be subclasses of the type in the declaration of the
array.

And yes, it is true, arrays cannot contain different value types
like int, long, double, float etc.

# re: Interview Questions: C#,asp.net,vb.net
10/8/2006 11:48 PM jyotsna
I m preparing for interview, please send me C#,ASP.NET and
VB.NET questions with ANSWERS
On my khushijyotsna@gmail.c om

please send me.thanks

jyotsna
i m preparing for interview, please send me C#,ASP.NET and
VB.NET questions with ANSWERS

# re: Interview Questions: SOAP, UDI,
XML,Serialization,Remoting,Assembly,Exception
Handling 10/9/2006 2:25 AM Ashish Upadhyay
Dear All

I am preparing for interview in .Net Technology, So if any body
have Interview question or any other useful information
regarding above mentioned topics, then Please send me.

I am highly obelgied of him/her

Thank you

UncleSam89

I don't agree with General question #9.

Can you store multiple data types in System.Array?
No.

How about array of objects?

prasanthi
Its really very usefull.Thanks alot for all the people who spend
their valuable time in answering the questions.

Plz do post the question for 2+ experinced persons also

Mike
You really ought to correct #3 with respect to
http://blogs.crsw.com/mark/articles/252.aspx#2407 . I noticed
the same thing and immediately turned to msdn to confirm my
suspicion.

Mike
Er... and I really ought to correct that last comment to refer to
#4, not #3! =)

AM chinnappa
excellent thanks for the site

AM Pallavi
Good Collection of questions.
Thanks.

venkata kiran kumar

Put some more questions relating to IIS.

AM Singh
Nice questions ...

Include questions related to quot;debugging multithreaded
applicationsquot;.

PM Naveen Kumar B.N

Nice Questions.

It is simple to Understand and Interesting

Thanks
Naveen Kumar BN

PM Naveen Kumar B.N

Nice Questions.

It is simple to Understand and Interesting

Thanks
Naveen Kumar BN

PM raj shekhar
Visit this site for more question.

<a
href=www.geocities.com/softwarecodehelp/interview.html>ww
w.geocities.com/softwarecodehelp/interview.html</a>

querrty

http://www.grupowe-pijane-studentki.xpanienki.pl II <a
href=quot;http://www.sutki-brunetki.xpanienki.plquot;>sutki
brunetki</a> II
[URL=http://www.biurowy-striptiz.xpanienki.pl]biurowy
striptiz[/URL] II

PM KNK
Can u send me more questions on .net,c#,ADO.NET,
SQL,RDBMS.

knk_6@yahoo.com.

spebby
ADO.Net
8. What does the Dispose method do with the connection
object?

The Dispose method closes the connection. The Dispose method
and the Close method are equivalent. The first time a
connection object is created, a connection pool is created.
Subsequent instantiations of the connection object does not
create a new connection pool (unless the connection string
changes), a connection is retrieved from the pool. The
connection pool remains in memory until the application exits.

rajesh jaiswal
please send me technical interviews asked in IT companies

# Java Questions 11/13/2006 12:05 AM Sarat
Gollapudi
I am trying to write a generic method that takes an enum as
argument and returns list of name=value pairs contained in the
enum, i.e.. some thing like:
public <T extends Enum<T>> List<NV> getList(T t)
{
List list = new ArrayList<NV>(t.values().leng th);
for( T type : t.values())
{
list.add(new NV(type.na me(), type.toString()));
}

return list;
}

Javac is complaining about missing values() method in
java.lang.Enum. Do y know what am I doing wrong?
ou

Thanks,
Sarat

Prabahar.V.N
Nice Questions...
Can u Send me more Questions for ADO.Net, C#, Asp.Net.

nal_prabhaa@yahoo.co.in

Thanks
Prabhaa...

# Thanx for -C# 11/15/2006 10:48 PM Yogson
Tembhre
hello sir,
the qstn on C# are so useful 4me, i will thankful to you.
----yogson----

复
数据恢
good~

Sabyasachi Ghosh
Questions are very useful those who are preparing for the
interview.
I will be really obliged if you send more questions

Thanking you
sabyasachi

Sabyasachi Ghosh

interview.

Thanking you
sabyasachi

Sabyasachi Ghosh
interview.

C#

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