This provides huge collection (150+) of DOTNET Technology FAQs which are of "Difference Between" type. For further updates, please visit my blog @ http://onlydifferencefaqs.blogspot.in/

1. 1) What are the differences between DataReader and DataAdapter?
S.No DataReader DataAdapter
1 Works in Connected Mode Works in Disconnected Mode
2 Can have only one record at a time Can have more than 1 records
3 Is ForwardOnly and Readonly Can navigate front and back and editable
4 Faster Slower
2) What are the differences between DataSet and DataReader?
S.No DataSet DataReader
1 Works in Disconnected Mode Works in Connected Mode
2 Can navigate back and forth Can navigate forward only
3 Data is editable Data is Readonly
4 Can contain more than one table Can contain only one row at a time
and relationships
5 Slower as having more overhead Faster when compared with DataSet
3) What is the difference between DataSet.Copy() and DataSet.Clone()?
S.No DataSet.Copy() DataSet.Clone()
1 DataSet.Copy() copies both the DataSet.Clone() copies the structure of
structure and data the DataSet, including all DataTable
schemas, relations, and constraints and it
does not copy any data
4) What are the differences between RecordSet and DataSet?
S.No RecordSet DataSet
1 RecordSet provides data of one row DataSet is a data structure which
at an instant represents the complete table data at
the same time
2 RecordSet always needs an Open DataSet needs connection only for
connection to read the data from retrieving the data. After retrieve the
data sources data connection is not necessary
3 RecordSet is able to load the DataSet has the capability to store the
structure and data of only one table structure and data of multiple tables at a
at a time time
4 RecordSet does not support DataSet enforces data integrity by using
constraints of Databases Constraints
5) What are the differences between ADO and ADO.Net?
S.No ADO ADO.Net

2. 1 It supports connected model It supports disconnected model
2 It uses record set It uses data set
3 XML support is less XML support is more

3. 1.Difference between Typed DataSet and Untyped DataSet
S.No Typed DataSet Untyped DataSet
1 It provides additional methods, It is not as easy to use as strongly
properties and events and thus it typed dataset.
makes it easier to use.
2 They have .xsd file (Xml Schema They do not do error checking at the
definition) file associated with design time as they are filled at run
them and do error checking time when the code executes.
regarding their schema at design
time using the .xsd definitions.
3 We will get advantage of We cannot get an advantage of
intelliSense in VS. NET. intelliSense.
4 Performance is slower in case of Performance is faster in case of
strongly typed dataset. Untyped dataset.
5 In complex environment, strongly Untyped datasets are easy to
typed dataset's are difficult to administer.
administer.
6 Typed DataSets use explicit UnTyped DataSets use table and
names and DataTypes for their column collections for their members
members.
ex:
ex: ds.Tables["emp"].Columns["eno"].Rea
northwindDataSet.Products.Produ dOnly=true;
ctNameColumn.Caption =
"pnames";
2.Difference between DataView and DataTable
S.No DataView DataTable
1 Read-only i.e., DataView can be Read/Write i.e., Datatable can be used
used to select the data. to edit or select or delete or insert a
data.
2 Is a reference to an existing Can be created empty and then
DataTable. Cannot be populated
populated from scratch; must be
instantiated with a reference to an
existing DataTable.
3 Data is a reference to an existing Data takes storage space.
DataTable, and does not
consume space.

4. 4 Can sort or filter rows without Can add/edit/delete rows, columns,
modifying the underlying data. and data, and all changes are
Rows and columns can be hidden persistent.
and revealed repeatedly.
5 Can return a DataTable version Can be cloned
of the view
6 A live reference to a Is source data; does not contain
DataTable; any changes in the references
DataTable data is immediately
reflected in the view.
7 Supports calculated columns, Does not support calculated columns
which are columns with a value
calculated on the fly by
combining or manipulating other
columns.
8 Can hide or show selected No row or column hiding
columns
3.Difference between Connected and Disconnected Environment
S.No Connected Environment Disconnected Environment
1 Connected Environment needs a Disconnected Environment does not
constantly connection of user to need any connection.
data source while performing any
operation.
2 Only one operation can be Multiple operations can be performed.
performed at a time in connection
Environment.
3 DataReader is used in Connection DataSet is used in it.
Environment.
4 It is slower in speed. Disconnected Environment has a good
speed.
5 We get updated data in it. There is a problem of dirty read.
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5. 1) What are the differences between Inline code and Code Behind Code?
S.No Inline code Code Behind Code
1 Its within .aspx file Its in a external class file
2 Dynamically compiled Compiled prior to deployment and
linked with .aspx file
2) What are the differences between Global.asax and Web.Config?
S.No global.asax web.config
1 It is a class file It is an XML file
2 There can be only one for an There can be many if under different
application sub-folders
3 Can have Application and Session Cannot have Application and Session
events events
4 Need to be recompiled when No need to compile when changes are
changes are made made
3) What are the Differences between Server.Transfer and Response.Redirect?
S.No Server.Transfer Response.Redirect
1 The navigation happens on the The navigation happens on the client-
server-side ,so client history is side ,so client history is updated
not updated
2 Data can be persist across the Context.Items loses the persistence
pages using Context.Item
collection
3 No Round-trips Makes a Round-trip
4 Has Good encapsulation No
4) What is the difference between a custom control and a user control?
S.No User Control Custom Control
1 Is a file with the .ascx extension Is a file with the .dll extension
2 Can be only used with the Can be used in any number of
application applications
3 Language dependent They are language independent, a
control
created in c# can be used in vb.net
4 Cannot be added to Visual studio Can be added to Visual studio Toolbox
Toolbox
5 Inherits from Server controls and We have to develop from scratch ,
easy to create so comparatively
difficult
6 Generally used for static content Used when dynamic content is
required
5) What is the difference between Caching and Application?
S.No Caching Application
1 Cache have expire policy Application does not have expire
policy
2 Cache does not require explicit Application require explicit locking
locking
3 Cache has the Property of timeout, Application variables exist as long as

6. which allows us to control the the application is alive
duration of the Objects so cached
4 Output can be cached in 4 ways, Application does not have options as
 Page Output Caching like Cache object
 Page Partial Caching
 DataSource Caching
 Data Caching
5 It is accessible to page level to all It is accessible to both page level and
the users application level to all the users
6) What is the difference between web farm and web garden?
S.No Web farm Web garden
1 A web application running on A web application running on a single
multiple servers is called a web server that has multiple CPUs is
farm called a web garden
7) What is the difference between Application and Session Events?
S.No Application Event Session Event
1 Application events are used to Session events are used to initialize
initialize objects and data that we data that we want to keep throughout
do want to make available to all individual sessions, but that we do not
the current sessions of our web want to share between sessions
application
8) What is the difference between Session Cookies and Persistent Cookies?
S.No Session Cookies Persistent Cookies
1 Session Cookies do not have Persistent Cookies have an expiration
expiration date date. The expiration date indicates to
the browser that it should write the
cookie to the client’s hard drive
9) What are the differences between Server Controls and HTML Controls?
S.No Server Controls HTML Controls
1 Server Controls can trigger HTML Controls can trigger only
control-specific events on the page-level events on server (postback)
server
2 Data entered in a server control is Data is not maintained in an HTML
maintained across requests. Server control. Data must be saved and
controls retain state restored using page-level scripts
3 The Microsoft .NET Framework HTML controls have HTML attributes
provides a set of properties for only
each server control. Properties
allows us to change the server
control’s appearance and behavior
within server-side code
4 Server controls automatically We must detect browser in code or
detect browser and adapt display write for least common denominator
as appropriate
10) What are the differences between ViewState and Hidden fields?
S.No ViewState Hidden fields
1 This is used for pages that will This is used for pages that will
postback to itself postback to itself or to another page

7. 2 This is built in structure for This is not an inbuilt structure
maintaining state of a page
3 Security is more as data is hashed, Security is less when compared to
compressed and encoded ViewState
11) What is the difference between SQL Cache Notification and SQL Cache Invalidation?
S.No SQL Cache Notification SQL Cache Invalidation
1 Using SQL Cache Notification, Using SQL Cache Invalidation, we
we can generate notifications can make a cached item invalid that
when the data of a database on depends on the data stored in a SQL
which a cached item depends server database, when the data in the
changes SQL server database is changed
12) What is the difference between absolute time expiration and sliding time expiration?
S.No Absolute time expiration Sliding time expiration
1 In absolute time expiration, a In sliding time expiration, the time for
cached item expires after the which the item is cached is each time
expiration time specifies for it, incremented by its expiration time if it
irrespective of how often it is is accessed before completion of its
accessed expiration time
13) What is the difference between adding items into cache through Add() method and
Insert() method?
S.No Cache.Add() Cache.Insert()
1 Cache.Add() method also returns Cache.Insert() method adds only the
an object representing the item we item in the cache
have added in the cache ,besides
adding the item in the cache
2 It is not possible to replace an We can replace an existing item in the
existing item in the cache using cache using the Cache.Insert() method
the Cache.Add() method
14) What is the difference between page-level caching and fragment caching?
S.No Page-level caching Fragment caching
1 In Page-level caching, we cache In Fragment caching, we cache parts
a whole page of the web page such as a user control
added to the web page
15) What is the difference between Label control and Literal control?
S.No Label control Literal control
1 Final HTML code of a Label Final HTML code of a Literal control
control has an HTML tag contains only text, which is not
surrounded by any HTML tag
16) What is the difference between HyperLink control and LinkButton control?
S.No HyperLink control LinkButton control
1 A HyperLink control do not have A LinkButton control have Click and
Click and Command events Command events, which can be
handled in the code behind file of the
web page

8. 17) What is the difference between an HtmlInputCheckBox control and an
HtmlInputRadioButton control?
S.No HtmlInputCheckBox control HtmlInputRadioButton control
1 We can select more than one We can select only a single
HtmlInputCheckBox control from HtmlInputRadioButton control from a
a group of HtmlInputCheckBox group of HtmlInputRadioButton
controls controls
18) How a content page differs from a master page?
S.No Content page Master page
1 A content page does not have A master page has complete HTML
complete HTML source code source code inside its source file
19) How will you differentiate a submaster page from a top-level master page?
S.No Submaster page Top-level master page
1 Like a content page, a submaster Top-level master page has complete
page also does not have complete HTML source code inside its source
HTML source code file
20) What is the difference between a page theme control and a global theme?
S.No Page theme Global theme
1 A page theme is stored inside a A global theme is stored inside the
subfolder of the App_Themes Themes folder on a web server
folder of a web application
2 It can be applied to individual web It can be applied to all the web sites
pages of the web application on the web server
21) What is the difference between a default skin and a named skin?
S.No Default skin Named skin
1 A default skin does not have a A named skin has a SkinId attribute
SkinId attribute
2 It is automatically applied to all It is applied to a control explicitly by
the controls of the same type setting the SkinId property of the
present on a web page control from the Properties window
22) Differentiate Globalization and Localization
S.No Globalization Localization
1 Globalization is the process of Localization is the process of
identifying the specific portion of configuring a web application to be
a web application that needs to be supported for a specific language or
different for different languages locale
and isolating that portion from the
core of the web application
23) What are the differences between web.config and machine.config?
S.No web.config machine.config
1 This is automatically created This is automatically installed when
when we create an ASP.Net web we install Visual Studio. Net
application project
2 This is also called application This is also called machine level
level configuration file configuration file

9. 3 We can have more than one Only one machine.config file exists
web.config file on a server
4 This file inherits setting from the This file is at the highest level in the
machine.config configuration hierarchy

10. Difference between Web site and Web application
S.No Web site Web application
1 Can mix vb and c# page in single We can't include c# and vb page in single
website. web application.
2 Can not establish dependencies. We can set up dependencies between
multiple projects.
3 Edit individual files after Can not edit individual files after
deployment. deployment without recompiling.
4 Right choice when one developer Right choice for enterprise environments
will responsible for creating and where multiple developers work unitedly for
managing entire website. creating,testing and deployment.
i.e.,In web site development, i.e.,In Web application, different different
decoupling is not possible. groups work on various components
independently like one group work on
domain layer, other work on UI layer.
5 Web site is easier to create than Web Web application is more difficult to create
application than a Web site
Difference between Local storage and cookies
S.No Local storage Cookies
1 Good to store large amount of data, Good for small amount of data, up to 4KB
up to 4MB
2 Easy to work with the JavaScript Difficult to work with JavaScript
3 Local storage data is not sent to the All data is transferred to and from server, so
server on every request (HTTP bandwidth is consumed on every request
header) as it is purely at the client
side
4 No way to specify the time out Can specify timeout period so that cookies
period as the Cookies have data are removed from browser
Difference between Session and Cache
S.No Session Cache
1 Ssession retains state per user Cache is used for retaining state for
application scoped items.
2 Items put into a session will stay Items in the cache can expire (will be
there, until the session ends removed from cache) after a specified
amount of time. And also there is no guaranty
that objects will not be removed before their
expiration times as ASP.NET remove items
from cache when the amount of available
memory gets small. This process is called as
Scavenging.
3 The session state can be kept external This is not the case with the cache.
(state server, SQL server) and shared
between several instances of our web
app (for load balancing).

11. Difference between Datalist and Repeater
S.No Datalist Repeater
1 Datalist supports multiple columns Repeater doesn't support multiple columns
displaying and using repeat columns display,no repeat columns property
property
2 Datalist supports styles for formating Repeater does not provide styles
templates data[headerstyle,...]
3 Datalist rendering output[html Repeater performanace is better than Datalist
content]will be slow compare with
repeater.
Summary:
If the requirement can achieve using repeater and datalist,choose repeater for better performance

12. 1.Difference between ASP.NET and PHP
S.No ASP.NET PHP
1 Technology Availability: Technology Availability:
ASP.NET was launched by PHP was launched by Rasmus Lerdorf
Microsoft in the year 2002. in the year 1995.
2 Database: Database:
ASP.Net uses MS-SQL for For point of database connectivity PHP
connecting database but MS-SQL uses MySQL for the purpose of
can not be availed free from database connectivitybecasue its
Microsoft. highly flexiblilty nature. Another
important fact is that it will incurextra
expenditure because MySQL can be
accessed for free.
3 Cost: Cost:
We need to install Internet Linux can be used for running PHP
Information Server (IIS)on a programs and Linux is free operating
Windows server platformif you system. Therefore,the cost of
want to run ASP.Net program. As developing a website in PHP language
Windows server platform is not a is remarkably low
free product,the cost of production
is bounded to be increased.
4 Run Time : Run Time:
It has been observed that ASP.Net Whereas inbuilt memory space is used
code runs slower than PHP code. by PHP while running.
This is becauseASP.Net utilizes
server space while running
5 Coding Simplicity: Coding Simplicity:
ASP.Net codes are somewhat PHP codes are very simple and a
complicated and a web developer programmer does not haveto make a
needs to work hard to get the hang diligent effort because it is
of it comparatively easier than other types
of programming languages.
6 Platform Connectivity Issue : Platform Connectivity Issue:
ASP.NET codes are usually run on PHP has a unique advantagein this
Windows platforms but if you issue. Its codes can be linked with
install ASP-Apache inthe server different types of platforms such
than it can run on Linux platform asWindows, Linux and UNIX.
as well.
7 Cost of Tools : Cost of Tools :

13. There is no such free tools are PHP codes are available for free in
available for ASP.Net. various forums and blogs as it is a
open source software. Furthermore,
some useful tools that can be used in
PHP are also availablefor free
8 Language Support : Language Support :
The syntax of ASP.Net is more or The codes that are used in PHP are
less similar to that of Visual basic very much similar to that of C++
syntax and this is all but simple. language and its syntax resembles the
syntax used in C and C++. Therefore,
if you have a fair knowledge in C++ or
C, you will not face any difficulty
while coding PHP language.
9 Security : Security :
ASP. Net is reputedfor creating Though PHP can offer enough
sophisticated techniques to ensure measures for ensuring data security
the safety of confidential
data.This is the reason why
government organizations opt for
ASP.Net.
2.Difference between ASP and ASP.NET
S.No ASP ASP.NET
1 ASP is a request response model. ASP.NET is a programming model that
is event driven.
2 ASP code is an interpreted ASP.NET is a compiled CLR code that
language that is interpreted by the will be executed on the Server.
script engine.
3 HTML and the coding logic are The code and design logic is separated
mixed in ASP. in ASP.NET.
4 To develop and debug ASP ASP.NET application can be
application, there are very limited developed and debugged using various
tools. tools including the leading Visual
Studio .NET tool.
5 ASP has limited support to Object ASP.NET is a complete Object
Oriented Programming principles. Oriented Programming language.
6 Session management and ASP.NET extends complete support
application state management is for session management and

14. very limited in ASP. application state management.
7 Error handling system is poor in ASP.NET offers complete error
ASP. handling and exception handling
services.
8 ASP does not offer any in-built In ASP.NET, data exchange is easily
support for the XML. performed using XML support.
9 Data source support is not fully Data source support is fully distributed
distributed in ASP. in ASP.NET.
3.Difference between ASP.NET and VB.NET
S.No ASP.NET VB.NET
1 ASP.NET is web technology that VB.NET is a language that is used in
is used in building web writing programs that are utilizing the
applications and websites. ASP.NET framework.
2 ASP.NET is a server side VB.NET is a .NET programming
technology that is language language. VB.NET is used to create
independent. Any .NET languages ASP.NET web applications or
such as C#, VB.NET can be used windows applications using Visual
to develop web applications Studio Windows Forms Designer or
through ASP.NET. mobile applications or console
applications or applications for variety
of other purposes.
3 ASP.NET is included within VB.NET is not part of .NET
the .NET framework. framework.
For example, ASP.NET contains For example, VB.NET is the code that
the text boxes and the controls is written on various events of text
that can be dragged and dropped boxes and controls to make them
into a web form. function as per the requirement.
4 ASP.NET contains server VB.NET does not include server
controls. controls.
5 ASP.NET can support all .NET VB.NET can support only scripting
languages. languages.

15. 4.Difference between Java and .NET
S.No Java .NET
1 JAVA is developed by ‘Sun .NET is developed by ‘Microsoft’.
Microsystem‘
2 JAVA is a programming .NET is a framework that supports
language many programming languages like
C#,ASP,VB.
3 In JAVA, JVM(Java Virtual In .NET CLR(common language
Machine) execute the code and Runtime) execute the code with two
convert source code to byte code. phase compilation.
4 JAVA can run on any operating .NET can run only on windows/IIS.
system
5 But in JAVA it depends upon the Although .NET support both explicit
programmer to destroy the and implicit garbage
garbage memory. collection,especially,in .NET the
garbage collector destroy the garbage
value in an efficient manner as
compared to JAVA.
6 JDBC is used for database ADO .NET is use for database
connection in JAVA connection in .NET.
7 For java many third party IDEs .net has a standard development IDE
are available. i.e. Microsoft Visual Studio
8 But web application in java run on Both windows and web applications
any operating system. can developed by .net but it will be
more better to go for windows
application with .NET . you can also
go for web application with .NET but
it will only hosted on windows server.
9 Exception Handling in Java is Exception Handling in .NET is
harder than .NET simpler than JAVA.
10 JAVA uses bootclasspath for .NET uses GAC(Global Assembly
completely trusted codes. Cache) and keep trusted assemblies.
11 Java is less secure than .NET JAVA and .NET both have similar
while providing security security goals. But .NET is more
secure because of its simple and clean
designs.
12 Java JDBC which requires .Net due to disconnected data access
multiple round trips to data base. through ADO.Net has high level of
Hence, performance is lesser performance against Java JDBC
than .NET

16. 13 Development is comparatively Due to Microsoft Visual Studio,
slower. development is faster.
14 Java applications development Microsoft Visual Studio installation
can be done on even less requires higher configuration system.
configuration computer system.
15 Java can only communicate with .Net is the platform itself for a
java programs multitude of languages. One can use C,
C++ and VB to program upon .net.
These programs interact with each
other using common methods. these
common methods are defined by .Net,
and are used by the programs to
communicate with each other without
worry about that language the program
was written in. the machine running
the program/s will need the .Net
platform to be installed.
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17. 1.Difference between HTTP and HTTPS
S.No HTTP HTTPS
1 URL begins with “http://" in case URL begins with “https://” in case of
of HTTP HTTPS.
2 HTTP is unsecured HTTPS is secured.
3 HTTP uses port 80 for HTTPS uses port 443 for
communication communication.
4 HTTP operates at Application HTTPS operates at Transport Layer.
Layer
5 No encryption is there in HTTP HTTPS uses encryption.
6 No certificates required in HTTP certificates required in HTTPS.
7 Most internet forums will HTTPS should be used in Banking
probably fall into this category. Websites, Payment Gateway, Shopping
Because these are open discussion Websites, Login Pages, Emails (Gmail
forums, secured access is offers HTTPS by default in Chrome
generally not required browser) and Corporate Sector
Websites. For example:
PayPal: https://www.paypal.com
Google AdSense:
https://www.google.com/adsense/
2.Difference between GET and POST methods
S.No GET POST
1 Post Mechanism: Post Mechanism:
GET request is sent via URL. Post request is sent via HTTP request
body or we can say internally.
2 Form Default Method: Form Default Method:
GET request is the default We have to specify POST method
method. within form tag like <Form
method="POST".......
3 Security: Security:
Since GET request is sent via Since Post request encapsulated name
URL, so that we can not use this pair values in HTTP request body, so
method for sensitive data. that we can submit sensitive data
through POST method.

18. 4 Length: Length:
GET request has a limitation on POST request has no major limitation.
its length. The good practice is
never allow more than 255
characters.
5 Caching or Bookmarking: Caching or Bookmarking:
GET request will be better for POST request is not better for caching
caching and bookmarking. and bookmarking.
6 SEO: SEO:
GET request is SEO friendly. POST request is not SEO friendly.
7 Data Type: Data Type:
GET request always submits data POST request has no restriction.
as TEXT.
8 Best Example: Best Example:
SEARCH is the best example for LOGIN is the best example for POST
GET request. request.
9 HTTP Request Message HTTP Request Message Format:
Format:
1 POST /path/script.cgi HTTP/1.0
1 GET /path/file.html? 2 From: umarali1981@gmail.com
SearchText=Interview_Question 3 User-Agent: HTTPTool/1.0
HTTP/1.0 4 Content-Type: application/x-www-
2 From: umarali1981@gmail.com form-urlencoded
3 User-Agent: HTTPTool/1.0 5 Content-Length: 8
4 [blank line here] 6
7 Code=132
Some comments on the limit on QueryString / GET / URL parameters Length:
1. 255 bytes length is fine, because some older browser may not support more than that.
2. Opera supports ~4050 characters.
3. IE 4.0+ supports exactly 2083 characters.
4. Netscape 3 -> 4.78 support up to 8192 characters.
5. There is no limit on the number of parameters on a URL, but only on the length.
6. The number of characters will be significantly reduced if we have special characters like spaces
that need to be URLEncoded (e.g. converted to the '%20').
7. If we are closer to the length limit better use POST method instead of GET method.

19. 3.Difference between User Controls and Master Pages
S.No User Controls Master Pages
1 Its extension is .ascx. Its extension is .Master.
2 Code file: .ascx.cs or .ascx.vb code file: .master.cs or .master.vb
extension
3 A page can have more than one Only one master page can be assigned
User Controls. to a web page
4 It does not contain It contains ContentPlaceHolder.
Contentplaceholder and this
makes it somewhat difficult in
providing proper layout and
alignment for large designs.
5 Suitable for small designs(Ex: More suitable for large designs(ex:
logout button on every .aspx defining the complete layout of .aspx
page.) page)
6 Register Tag is added when we MasterPageFile attribute is added in
drag and drop a user control onto the Page directive of the .aspx page
the .aspx page. when a Master Page is referenced in
.aspx page.
7 Can be attached dynamically Can be referenced using Web.Config
using LoadControl method.PreInit file also or dynamically by writing
event is not mandatory in their code in PreInit event.
case for dynamic attachment.
4.Difference between Build and Rebuild
S.No Build Rebuild
1 A build compiles only the files A rebuild rebuilds all projects and files
and projects that have changed. in the solution irrelevant of whether
they have changed or not.
2 Build does not updates the xml- Rebuild updates the xml-
documentation files documentation files
Note: Sometimes,rebuild is necessary to make the build successful. Because, Rebuild cleans
Solution to delete any intermediate and output files, leaving only the project and component files,
from which new instances of the intermediate and output files can then be built.

20. 5.Difference between generic handler and http handler
S.No Generic Handler Http Handler
1 Generic handler has a handler http handler is required to be
which can be accessed by url with configured in web.config against
.ashx extension extension in web.config.It does not
have any extension
2 Typical example of generic For http handler, page handler which
handler are creating thumbnails of serves .aspx extension request and give
images response.
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21. 1.Difference between ViewState and SessionState
S.No ViewState SessionState
1 View state is maintained in page Session state is maintained in session
level only. level.
2 View state of one page is not Session state value is available in all
visible in another page.i.e., when pages within a user session.i.e., The
user requests another page data will be no longer available if user
previous page data will be no close the browser or session timeout
longer available. occurs.
3 View state information stored in Session state information stored in
client only. server.
4 View state persist the values of Session state persist the data of
particular page in the client particular user in the server. This data
(browser) when post back available till user close the browser or
operation done. session time completes.
5 View state used to persist page- Session state used to persist the user-
instance-specific data. specific data on the server side.
2.Difference between ViewState and ControlState
S.No ViewState ControlState
1 ViewState can be disabled Control State cannot be disabled.
2 ViewState is implemented by Control State works even when
using EnableViewState property EnableViewState is off.
of a control to true. To use Control State (for example in a
custom control) we have to override
OnInit method,call
RegisterRequiresControlState method
in OnInit method and then override the
SaveControlState and
LoadControlState methods.
3 ViewState is used to maintain Control State is used for small data
page-level state for large data only.
eg: maintain clicked page number in a
GridView even when EnableViewState
is off

22. 3.Difference between SessionState and Cookies
S.No SessionState Cookies
1 Session can store any type of data Cookies can store only "string"
because the value is of datatype of datatype
"object"
2 These are stored at Server side They are stored at Client side
3 Session are secured because it is Cookie is non-secure since stored in
stored in binary format/encrypted text format at client side
form and it gets decrypted at
server
4 Session is independent for every Cookies may or may not be individual
client i.e individual for every for every client
client
5 There is no limitation on size or Due to cookies network traffic will
number of sessions to be used in increase.Size of cookie is limited to 40
an application and number of cookies to be used is
restricted to 20.
6 For all conditions/situations we Only in few situations we can use
can use sessions cookies because of no security
7 We cannot disable the We can disable cookies
sessions.Sessions can be used
without cookies also(by disabling
cookies)
8 The disadvantage of session is Since the value is string there is no
that it is a burden/overhead on security
server
9 Sessions are called as Non- We have persistent and non-persistent
Persistent cookies because its life cookies
time can be set manually
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23. New features of ASP.Net 2.0, ASP.Net 3.0 and ASP.Net 3.5- A
Comparative Chart
SNo ASP.Net 2.0 ASP.Net 3.0 ASP.Net 3.5
1 a) Generics a) Windows a) Linq for SQL, XML, Dataset,
b) Anonymous Communication Object
methods Foundation (WCF), b) Addin system
c) Partial class formerly called c) p2p base class
d) Nullable type Indigo; a service- d) Active directory
e) The new API gives oriented messaging e) ASP.NET Ajax
a fine grain control system which allows f) Anonymous types with
on the behavior of programs to static type inference
the runtime with interoperate locally g) Paging support for
regards to or remotely similar to ADO.NET
multithreading, web services. h) ADO.NET synchronization
memory b) Windows API to synchronize local
allocation, Presentation caches and server side
assembly loading Foundation (WPF), datastores.
and more formerly called i) Asynchronous network I/O
f) Full 64-bit support Avalon; a new user API
for both the x64 interface subsystem j) Support for HTTP
and the IA64 and API based on pipelining and syndication
hardware XML and vector feeds.
platforms graphics, which uses k) New System.CodeDom
g) New 3D computer namespace.
personalization graphics hardware
features for and Direct3D
ASP.NET, such as technologies.
support for c) Windows Workflow
themes, skins and Foundation (WF)
webparts. allows for building of
h) .NET Micro task automation and
Framework integrated
transactions using
workflows.
d) Windows CardSpace,
formerly called
InfoCard; a software
component which
securely stores a
person's digital
identities and

24. provides a unified
interface for
choosing the identity
for a particular
transaction, such as
logging in to a
website

25. 1.Difference between C# 3.5 and C# 4.0
S.No C# 3.5 C# 4.0
1 C# 3.5 does not support dynamic C# 4.0 supports dynamic programming
programming. through dynamic objects.
2 The dynamic keyword is not In C# 4.0, dynamic keyword is
recognized in C# 3.5. associated with objects to represent
them as dynamic objects.
3 Dynamic variables cannot be C# 4.0 allows creation of dynamic
created in C# 3.5. variables.
4 In C# 3.5, method parameters In C# 4.0, the method parameters can
cannot be specified with default be specified with default values using
values. C# 3.5 does not support optional parameters.
optional parameters.
5 In C# 3.5, method parameters C# 4.0 provides named parameters to
have to be specified in the same represent the values of method
order as in method declaration in parameters without following the order
the method call. C# 3.5 does not of declaration.
provide named parameters.
6 In C# 3.5, usage of ref keyword is In C# 4.0, usage of ref keyword is
mandatory while executing optional while executing methods
methods which are supplied by which are supplied by the COM
the COM interfaces. interfaces.
7 The COM object’s indexed The COM object’s indexed properties
properties are not recognized in are recognized in C# 4.0.
C# 3.5.
8 Co-variance and contra-variance C# 4.0 enhances Generics by
are not supported in Generics of introducing co-variance and contra-
C# 3.5. variance.
2.Difference between C# and VB.NET
S.No C# VB.NET
1 In C#, variables are declared using In VB.NET, the variables are declared
declarators. using keywords such as private,
protected, friend, public, static, shared
and Dim.
2 In C#, an object can only be In VB.NET, an object can be created
created using new. using new and CreateObject().
3 In C#, void is specified as the In VB.NET, Sub is used in method
return type when a method does declaration to indicate that the method

26. not return a value. does not return any value.
4 In C#, no keyword is required to In VB.NET, Overloads keyword is
indicate an overloaded method. used to indicate an overloaded method.
5 The current object is referred The current object is referred as me in
using this pointer in C#. VB.NET.
6 Non virtual call cannot be made in To make a non-virtual call to the
C#. current object’s virtual method,
MyClass is used in VB.NET.
7 Compound data type is declared Compound data type is declared in
in C# using class, struct and VB.NET using Structure.
interface.
8 In C#, constructors are used to In VB.NET, Sub New() is used to
initialize an object. initialize the newly created object.
9 Object cleanup can be explicitly Object cleanup can be done by using
done by destructor in C#. Finalize method in VB.NET.
10 In C#, an object is subject to In VB.NET, an object cannot be
asynchronous modification using modified in an asynchronous way.
volatile keyword.
11 In C#, all the variables have to be In VB.NET, variables can be forced for
declared before being used. explicit declaration using Option
Explicit.
12 In C#, default property is defined In VB.NET, default property is defined
by using indexers. using Default.
13 In C#, base class can be referred In VB.NET, base class can be referred
using the keyword ‘base’. using the keyword ‘MyBase’.
14 Abstract class of C# can only be MustInherit keyword of VB.NET is
inherited and not instantiated. used to denote that a class can only be
inherited and not instantiated.
15 Sealed keyword of C# is used to NotInheritable keyword of VB.NET
denote that a class cannot be denotes that the class cannot involve in
inherited. inheritance.
16 Division can be performed in C# Division can be performed in VB.NET
using / operator. using operator.
17 Remainder of division can be Remainder of division can be retrieved
retrieved using mod operator of using %.
C#.
18 C# does not have exponentiation In VB.NET, exponentiation can be
operator. performed using ^ operator.

27. 19 C# has Bitwise operators namely Bitwise operators in VB.NET are And,
&,| and ^. Or, Xor.
20 Object reference variables can be Object reference variables can be
compared using == operator in compared using Is operator in
C#. VB.NET.
21 The short ciruit operators in C# The short circuit operators in VB.NET
are && (Boolean AND) and || are AndAlso (Boolean AND) and
(Boolean OR). OrElse (Boolean OR).
3.Difference between C# and C++
S.No C# C++
1 C# is a high level language that is C++ is a low level and indeed platform
component oriented. neutral programming language.
2 When compiled, C# code is When compiled, C++ code is
converted into Intermediate converted into assembly language
language code. This intermediate code.
language code is converted into
executable code through the
process called Just-In-Time
compilation.
3 In C#, memory management is In C++, the memory that is allocated in
automatically handled by garbage the heap dynamically has to be
collector. explicitly deleted.
4 In C# Switch Statement, the test In C++ Switch Statement, the test
variable can be a string. variable cannot be a string.
5 In C# switch statement, when In C++ switch statement, when break
break statement is not given, the statement is not given, the fall through
fall through will not happen to the will happen to the next case statement
next case statement if the current even if the current case statement has
case statement has any code. any code.
6 In addition to for, while and C++ does not contain for each
do..while, C# has another flow statement.
control statement called for each.
7 C# struts can contain only value C++ struts behave like classes except
types. The struts is sealed and it that the default access is public instead
cannot have a default no-argument of private.
constructor.
8 In C#, delegates, events and In C++, only variables, constructors,
properties can also be specified as functions, operator overloads and
class members. destructors can be class members.

28. Delegates, events and properties
cannot be specified as class members.
9 In C#, the end of the class In C++, the end of the class definition
definition has a closing brace has a closing brace followed by a
alone. semicolon.
10 The access modifiers in C# are The access modifiers in C++ are
public, private, protected, internal public, private, protected. C++ does
and protected internal. not have internal and protected internal
access modifiers.
11 C# has finally block in exception C++ does not have finally block in
handling mechanism. The code exception handling mechanism.
statements in the finally block will
be executed once irrespective of
exception occurrence.
12 The exception in C# can only The exception in C++ can throw any
throw a class that is derived from class.
the System.Exception class.
13 C# does not have the concept of C++ has the concept of function
function pointers. C# has a similar pointers.
concept called Delegates.
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29. 1. Difference between Factory Pattern and Abstract Factory Pattern
S.No Factory Pattern Abstract Factory Pattern
1 Create object through inheritance Create object through composition
2 Produce only one product Produce families of products
3 Implements code in the abstract creator Concrete factories implements factory
that make use of the concrete type that method to create product
sub class produces
2.Difference between Abstract Factory Pattern And Builder Pattern
S.No Builder Pattern Abstract Factory Pattern
1 In Builder Pattern, there will be one Abstract Factory Pattern will return the
Director class which will instruct Builder instance directly.
class to build the different
parts/properties of our object and finally
retrieve the object.
2 It will have reference to the created It does not keep the track of it's created
object. object.
3.Difference between Builder Pattern And Composite Pattern
S.No Builder Pattern Composite Pattern
1 It is used to create group of objects of It creates Parent - Child relations between
predefined types. our objects.
4.Difference between MVC and MVP
S.No MVP MVC
1 MVP is a bit more complex to MVC is easier to implement than MVP.
implement than MVC .Also, it has
additional layer for view interfaces.
2 The request is always received by the The request is received by the controller
View and delegated to the presenter which in turn gets the required data and
which in turn gets the data does the loads up the appropriate view
processing
3 The presentation and view logic an be The controller logic can be unit tested.
unit tested as the view is loosely Note: We can unit test view if we are using
coupled. Razor view engine. ASPX viewengine are
not that easily unit testable
4 MVP is best suitable for Windows MVC is best suitable for Web Programming.
Programming as the flow naturally tend
towards this pattern.

30. 5.Difference between Proxy Pattern and Observer Pattern
S.No Proxy Pattern Observer Pattern
1 The Proxy Pattern is used for wrapping a The Observer Pattern is used by a publisher
kind of special object with 1 or more object to notify subscriber objects with
other objects. information.
2 Either because we don't always have the The publisher object does not know the
wrapped object or because it needs to be subscribing objects - except that the
managed in a certain way that can be conform to a certain subscriber interface.
simplified via the proxy object(s). This is This is a very flexible pattern for
kind of a way to exchange the API of an distributing events, since those that wants to
existing class with a proxy class. We are listen on certain object has the power to do
not just talking events here, but whatever so without changing the code of the
kind of functionality to define via the publishing object.
proxy object instead of the real object.
6. Difference between Singleton Pattern and a static class
S.No Singleton Pattern static class
1 Singleton pattern maintains single We cannot create instance for static class.
instance.
2 A singleton can extend classes and A static class cannot .
implement interfaces. Note: It can extend classes, but it does not
inherit their instance members.
3 A singleton can be initialized lazily or A static class is generally initialized when it
asynchronously. is first loaded, leading to potential class
loader issues.
4 Singletons can be handled static class cannot be handled
polymorphically without forcing their polymorphically.
users to assume that there is only one
instance.
5 Singleton Class can have value when Static are always just shared and have no
Class object instantiated between server instance but multiple references.
and client, such a way if three client
want to have a shared data between them
Singleton can be used.Thats why
singleton class can be used for state
mangement in stateless scenarios like
shopping cart scenario.
6 We can pass singleton object as We cannot pass parameter in static class
parameter
7 Singleton provides flexibility and also Static classes once defined could not
provides sort of a mechanism to control accomodate any future design changes as by
object creation based on various design static classes are rigid and cannot be
requirements. They can be extended as extended.
well if need arises. In other words we
are not always tied to a particular
implementation. With Singleton we

31. have the flexibility to make changes as
when situation demands.
7.Difference between Strategy and Inversion of Control (IOC)
S.No Strategy Pattern Inversion of Control (IOC) Pattern
1 The strategy pattern is useful when we Inversion of Control/Dependency Injection
want classes to depend on the interface (IoC/DI) comes into play when we want the
rather than the implementation.And we concrete strategy implementation injected
can easily swap out behavior depending into a class. For example, we could use the
on which concrete implementation we DI Framework Ninject and configure it so
provide. that it will know which concrete strategy
implementation to inject into a class in
specific scenarios.
Note: Strategy is just one of the ways that
IOC is implemented
8.DIfference between IDictionary and Dictionary
S.No IDictionary Dictionary
1 IDictionary is just a contract, abstraction Dictionary is concrete implementation.
2 It is recommended for example to expect Argument or Property is not required for
as argument an IDictionary rather than Dictionary.
concrete Dictionary, or to expose
property of IDictionary rather than
Dictionary, because this promotes loose
coupling. Than we are able to change
underlying objects in the future without
affecting those who use your object.
9.Difference between Factory Pattern and Dependency Injection
S.No Factory Pattern Dependency Injection(DI)
1 Factory is used to create objects DI is used to move the responsibility of
creating an object outside the main code.
2 Some of the well known framework
available for DI are
1. Unity Application Block (Microsoft)
2. Ninject
3. StructureMap
4. Castle Windsor
5. Munq/Funq
6. Autofac

32. 10.Difference between String.Clone() and String.Copy() method
S.No String.Clone() String.Copy()
1 Returns a reference to this instance of Creates a new instance of String with the
String. same value as a specified String.
i.e., it gives pointer value(ie Current i.e., it creates an instance in Heap Memory
memory Reference) and gives pointer value(ie New Memory
Reference)
11.Difference between Strategy Pattern and Factory Pattern
S.No Strategy Pattern Factory Pattern
1 Strategy's sole intent to is to provide a Factory's sole purpose is to create objects .
mechanism to select different algorithm.
2 We cannot use "strategy" to create We can use "factory" to create objects of
objects of "factory". "strategy".
12.Difference between Proxy and Adaptor
S.No Proxy Pattern Adaptor Pattern
1 Proxy on the other hand represents a Adapter is used to adapt to incompatible
standin object for the real object. This is interfaces. It's more directed from the client
required when the real object is complex (those who consume the object) perspective.
to create, is not available, or for A client expects an interface to be of
authentication purpose. For e.g. web particular type and adapter plays a role in
service proxy, proxy authentication filling that gap.
server etc.
It's more from making it easier for the client
Proxy can be categorized into to adapt to other third party libraries within
there own by adapting to it.
Virtual Proxy
Remote Proxy
Protection Proxy
13.Difference between Decorator and Visitor
S.No Decorator Pattern Visitor Pattern
1 Decorator may have just a single object Visitor has a tree of objects to be worked
to customize. upon.
2 Decorator does not require a traverser Visitor requires a traverser for successful
for successful implementation. implementation.
3 Decorator pattern is a structural pattern Visitor pattern is Behavioral pattern that
that help us to add new function to an seperate the data structure from the
object in the run time , note that in the operation (functionality ) that work on it ,
run time not design time . this mean we can add different operation on
the same data structure

34. Difference between ASP.Net 2.0 and ASP.Net 3.5
SN Feature ASP.Net 2.0 ASP.Net 3.5
o
1 New ASP.Net 2.0 includes the ASP.Net 3.5 includes the
Features following as new features, following as new features,
a) Master Pages a) ListView Control
b) Profiles b) DataPager Control
c) GridView Control c) Nested Master Pages
d) LinqDataSource Control
2 Multi- ASP.Net 2.0 does not ASP.Net 3.5 supports multi-
targeting support Multi-Targeting targeting. It means that we
environment. choose from a drop-down list
whether to have Visual Studio
2008 build applications against
the ASP.NET 2.0, 3.0, or 3.5
frameworks.
3 AJAX There is no in-built support In ASP.Net 3.5, AJAX is
Support for AJAX in ASP.Net 2.0. integrated into the .NET
Instead, it has to be Framework, thereby making the
downloaded and installed. process of building intuitive cool
user interfaces easier.
4 Siverlight It does not support It supports Siverlight.
Support Siverlight.
5 Javascript It does not provide It provides Javascript debugging.
Debugging Javascript debugging.
6 LINQ It does not support LINQ. It Supports Language Integrated
Support Query (LINQ).

35. 1) What is the difference between CCW and RCW?
S.No CCW RCW
1 COM to .NET communication .NET to COM Communication happens
happens through COM Callable through Runtime Callable Wrapper
Wrapper
2) What are the differences between Dll and Exe?
S.No Dll Exe
1 Objects of Dlls can be created Objects of Exe cannot be created
2 Dll is In-Process Exe is Out-Process
3 It cannot be started as a standalone It can be started as a standalone
3) What are the differences between Managed Code and Unmanaged Code?
S.No Managed Code Unmanaged Code
1 It is executed under CLR It is not executed under CLR
2 It compiles to intermediate language It compiles directly to machine code
3 It provides services like security, It does not provide security, exception
exception handling, garbage handling, garbage collection etc
collection etc
4 It can access both managed and It can access only unmanaged code
unmanaged code

36. Difference between hash table and arraylist
S.No Arraylist Hash table
1 Array List is a List Hash Table is a map
2 Here, we can only add items to the list Here, we can add data with the key
3 Retrieving data using Arraylist is slower Retrieving by key in Hashtable is faster than
than Hashtable because If we want to retrieving in Arraylist because If we want to
find something in a arraylist we have to find something in a hashtable we dont have
go through each value in arraylist. to go through each value in hashtable,
instead search for key values and is faster.
Difference between Hash Table and Arrays
Hash Table Array
Hash table stores data as name,value pair. Array stores only value
To access value from hash table, we need to In array, to access value , we need to pass
pass name. index number.
We can store different type of data in hash In array ,we can store only similar
table, say int,string etc. type of data.
Difference between Dictionary and Hashtable
Dictionary Hashtable
Dictionary is a generic type Hashtable is not generic type.
In Dictionary we need to specify the types of Hashtable is a collection of name/value pairs
both the key and the corresponding value.The that are organised on the basis of hash code of
value represents the actual object stored and the the key being specified.
key represents a means to identify a particular
object.
In Dictionary public static members are type Hashtable is thread safe for use by multiple
safe but any instance members are not type reader threads and a single writing thread.
safe.
We cannot use Dictionary with Web Services We can use Hashtable withWeb Services
The reason is no web service standard supports
generic standard.
Dictionary is aster than Hashtable because It is slower than dictionary because to retrieve
boxing is not required. a value we must cast it as its actual type,
because it will be returned via object reference.

37. Difference between array and stack
Array Stack
An array can be multi-dimensional Stack is strictly one-dimensional
An array allows direct access to any of its With a stack, only the 'top' element is directly
elements accessible; to access other elements of a stack,
we must go through them in order, until we
get to the one we want
Difference between Stack and Heap
Stack Heap
Memory will be allocated at the compile time. Memory will be allocated at the run time.
Here the memory is allocated by the compiler. Here the memory is allocated by the user.
Memory will be allocated only in sequential Memory will be allocated in sequential
locations. locations and non- sequential locations.
The memory will also be deleted by the The memory must be deleted explicitly by the
compiler. user.
There is lot of chance of memory wastage. There is no chance of memory wastage if the
memory is handled perfectly.
Difference between Array and ArrayList
Array ArrayList
They are fixed length. They are resizable and variable length
They are compiled strong type collection. They are flexible and can accommodate any
data types.
Because arrays are of fixed size and strong In arraylist lots of boxing and unboxing are
type collection performance is faster. done there for its performance is slower.
Array is in the System namespace ArrayList is in the System.Collections
namespace.
Ex:Char[] vowel=new Char[]; Ex:ArrayList a_list=new ArrayList();

38. 1.Difference between for and foreach loop
S.No For loop Foreach loop
1 In case of for the variable of the loop is In case of Foreach the variable of the loop
always be int only. while be same as the type of values under the
array.
2 The For loop executes the statement or The Foreach statement repeats a group of
block of statements repeatedly until embedded statements for each element in an
specified expression evaluates to false. array or an object collection.
3 There is need to specify the loop We do not need to specify the loop bounds
bounds(Minimum, Maximum). minimum or maximum.
4 example: example:
using sytem; using sytem;
class class1 class class1
{ {
static void Main() static void Main()
{ {
int j=0; int j=0;
for(int i=0; i<=10;i++) int[] arr=new int[]
{ {0,3,5,2,55,34,643,42,23};
j=j+1; foreach(int i in arr)
} {
Console.ReadLine(); j=j+1;
} }
} Console.ReadLine();
}
}
2. Difference between Covariance and Contravariance
S.No Covariance Contravariance
1 Converting from a broader type to a Converting from a more specific type to a
specific type is called co-variance.If B broader type is called contra-variance. If B is
is derived from A and B relates to A, derived from A and B relates to A, then we
then we can assign A to B. Like A=B. can assign B to A. Like B= A. This is
This is Covariance. Contravariance.
2 Co-variance is guaranteed to work Contra-variance on the other hand is not
without any loss of information during guaranteed to work without loss of data. As
conversion. So, most languages also such an explicit cast is required.
provide facility for implicit conversion.
e.g. Converting from cat or dog to animal is
e.g. Assuming dog and cat inherits from called contra-variance, because not all
animal, when you convert from animal features (properties/methods) of cat or dog is
type to dog or cat, it is called co- present in animal.
variance.
3 Example:

39. class Fruit { }
class Mango : Fruit { }
class Program
{
delegate T Func<out T>();
delegate void Action<in T>(T a);
static void Main(string[] args)
{
// Covariance
Func<Mango> mango = () => new Mango();
Func<Fruit> fruit = mango;
// Contravariance
Action<Fruit> fr = (frt) =>
{ Console.WriteLine(frt); };
Action<Mango> man = fr;
}
}
4 Note:
1. Co-variance and contra-variance is possible only with reference types; value types
are invariant.
2. In .NET 4.0, the support for co-variance and contra-variance has been extended to
generic types. No now we can apply co-variance and contra-variance to Lists etc. (e.g.
IEnumerable etc.) that implement a common interface. This was not possible with
.NET versions 3.5 and earlier.

40. 3.Difference between IList and IEnumerable
S.No IList IEnumerable
1 IList is used to access an element in a IEnumerable is a forward only collection, it
specific position/index in a list. can not move backward and between the
items.
2 IList is useful when we want to Add or IEnumerable does not support add or remove
remove items from the list. items from the list.
3 IList can find out the no of elements in Using IEnumerable we can find out the no of
the collection without iterating the elements in the collection after iterating the
collection. collection.
4 IList does not support filtering. IEnumerable supports filtering.
4.Difference between IEnumerable and IQueryable
S.No IEnumerable IQueryable
1 IEnumerable exists in IQueryable exists in System.Linq
System.Collections Namespace. Namespace.
2 IEnumerable is best to query data from IQueryable is best to query data from out-
in-memory collections like List, Array memory (like remote database, service)
etc. collections.
3 While query data from database, While query data from database,
IEnumerable execute select query on IEnumerable execute select query on server
server side, load data in-memory on side with all filters.
client side and then filter data.
4 IEnumerable is suitable for LINQ to IQueryable is suitable for LINQ to SQL
Object and LINQ to XML queries. queries.
5 IEnumerable does not supports custom IQueryable supports custom query using
query. CreateQuery and Execute methods.
6 IEnumerable does not support lazy IQueryable support lazy loading. Hence it is
loading. Hence not suitable for paging suitable for paging like scenarios.
like scenarios.
7 Extension methods supports by Extension methods supports by IEnumerable
IEnumerable takes functional objects. takes expression objects means expression
tree.
8 IEnumerable Example
MyDataContext dc = new MyDataContext ();
IEnumerable list = dc.loyees.Where(p => p.Name.StartsWith("S"));
list = list.Take(10);
Generated SQL statements of above query will be :
SELECT [t0].[EmpID], [t0].[EmpName], [t0].[Salary] FROM [Employee] AS [t0]
WHERE [t0].[EmpName] LIKE @p0

41. Note: In this query "top 10" is missing since IEnumerable filters records on client side
IQueryable Example
MyDataContext dc = new MyDataContext ();
IEnumerable list = dc.loyees.Where(p => p.Name.StartsWith("S"));
list = list.Take(10);
Generated SQL statements of above query will be :
SELECT TOP 10 [t0].[EmpID], [t0].[EmpName], [t0].[Salary] FROM [Employee]
AS [t0]
WHERE [t0].[EmpName] LIKE @p0
Note: In this query "top 10" is exist since IQueryable executes query in SQL server
with all filters.
5.Difference between IEnumerable and IEnumerator
S.No IEnumerable IEnumerator
1 The IEnumerable interface is a generic IEnumerator provides two abstract methods
interface that provides an abstraction and a property to pull a particular element in
for looping over elements. a collection. And they are Reset(),
In addition to providing foreach MoveNext() and Current The signature of
support, it allows us to tap into the IEnumerator members is as follows:
useful extension methods in the void Reset() : Sets the enumerator to its
System.Linq namespace, opening up a initial position, which is before the first
lot of advanced functionality element in the collection.
The IEnumerable interface contains an bool MoveNext() : Advances the enumerator
abstract member function called to the next element of the collection.
GetEnumerator() and return an interface object Current : Gets the current element in
IEnumerator on any success call. the collection
2 IEnumerable does not remember the IEnumerator does remember the cursor state
cursor state i.e currently row which is
iterating through
3 IEnumerable is useful when we have IEnumerator is useful when we have to pass
only iterate the value the iterator as parameter and has to remember
the value

42. 1) What are differences between XML and HTML?
S.No XML HTML
1 XML provides user definable tags HTML provides defined set of tags
designed for web display
2 XML is content driven HTML is format driven
3 End tags are essential in a well End tags are not always
formed XML document. In a well required.<HTML> tag needs an
formed document, elements can be equivalent </HTML> tag but <br> tag
defined as single tag or a pair of tags does not require </br> tag
like <student/> or the <student>…
</student> pair
4 Quotes required around attribute Quotes are not required for the values
values of attributes
5 Slash required in empty tags Slash not required
6 XML is used for describing data HTML is used for designing pages

43. 1.Difference between LINQ and SQL
S.No LINQ SQL
1 LINQ Stands for language SQL stands for Structured
integrated query. Query Language.
2 LINQ Statements are verified SQL statements can be used in a
during compile time. application gets verified for their
syntaxes only in the run time.
3 To use LINQ we can depend upon To use SQL we need to be familiar
our .Net Language syntaxes and with SQL syntaxes and also the pre-
also we can consume base class defined functions of SQL like
library functionalities. MAX,MIN,LEN and SUBSTRING
etc...
4 LINQ Statements can be As SQL statements execute on
debugged as they execute under Database server debugging of the code
framework environment. is not possible.
SQL .
2.Difference between LINQ to SQL and Entity Framework
S.No LINQ to SQL Entity Framework
1 It only works with Sql server. It works with variety of db products.
2 Used for rapid application Cannot used for rapid application
development. development.
3 It does not support for complex It provides support for complex type.
type.
4 It cannot generate db from model. It can generate db from model.
5 Mapping type ( class to single Mapping type ( class to multiple
table) tables)
6 We can query data using We can query data using esql,object
DataContext. services,entity client and linq to
entities.
Another Good Reference:
http://jinaldesai.net/linq-to-sql-vs-entity-framework/
(OR)
http://www.slideshare.net/jinaldesailive/linq-to-sql-vs-entity-framework-jinal-desai

44. 3.Difference between LINQ and Stored Procedures
S.No LINQ Stored Procedures
1 As LINQ is part of .NET, we can It is really very hard to debug the
use visual studio’s debugger to Stored Procedure
debug the queries
2 With LINQ everything gets With Stored Procedures, we need to
complied into single DLL hence provide an additional script for
deployment becomes easy. deployment
3 LINQ is type safe, so queries Stored Procedures are not type safe
errors are type checked at compile i.e., error can be caught only during
time.It is really good to encounter runtime.
an error when compiling rather
than runtime exception!
4 LINQ supports multiple databases With Stored Procedures which need to
be re-written for different databases.
5 LINQ supports abstraction which As Stored Procedures does not support
allows framework to add abstaction , so it is difficult to add
additional improvements like additional impovements like multi
multi threading. It is much threading
simpler and easier to add this
support through LINQ than Stored
Procedures.
6 LINQ queries need to compile Stored Procedures are ster thn LINQ
before execution.Therefore, LINQ because they are precompiled i.e.,
is slower than Stored Procedures. Stored Procedures have a predictable
execution plan.Therefore, if a stored
procedure is being executed for the
second time, the database gets the
cached execution plan to execute the
stored procedure.
4.Difference between LINQ to SQL and LINQ to Objects
S.No LINQ to SQL LINQ to Objects
1 LINQ to SQL needs a Data LINQ to Objects does not need any
Context object. The Data Context intermediate LINQ provider or API.
object is the bridge between LINQ
and the database.
2 LINQ to SQL returns data of type LINQ to Objects returns data of type
IQueryable<T> IEnumerable<T>.

45. 3 LINQ to SQL is translated to SQL LINQ to Objects does not need to be
by way of Expression Trees, translated.
which allow them to be evaluated
as a single unit and translated to
the appropriate and optimal SQL
statements.
4 LINQ to SQL is translated to SQL LINQ to Objects is executed in the
calls and executed on the local machine memory.
specified database
5.Difference between LINQ to SQL and LINQ to Entities
S.No LINQ to SQL LINQ to Entities
1 Does not support Conceptual Data Supports Conceptual Data Model
Model
2 Does not support Storage Schema Supports Storage Schema
3 Does not support Mapping Schema Supports Mapping Schema
4 Does not support New Data Access Supports New Data Access Provider
Provider
5 Does not support Non-SQL Server Supports Non-SQL Server Database
Database Support Support
6 Supports Direct Database Does not support Direct Database
Connection Connection
7 Does not support Multiple-table Supports Multiple-table Inheritance
Inheritance
8 Does not support Single Entity from Supports Single Entity from Multiple
Multiple Tables Tables

46. 1.Difference between LINQ to SQL and ADO.NET
S.No LINQ to SQL ADO.NET
1 Used for data handling with SQL Used for data handling with any
Server databases only. database: SQL
Server/Access/Oracle/Excel etc.
2 Uses the extension methods of Does not use the extension methods of
System.Linq.Queryable class. System.Linq.Queryable class.
3 Introduced in .net Framework 3.0 It is there since the .net Framework 1.0
4 DataContext is used for Database SqlConnection/OleDbConnection are
connectivity. used for database connectivity
5 Syntax and coding is somewhat Easier syntax and coding.
complex.
Note: Both LINQ TO SQL and ADO.NET have connected / disconnected modes of data
handling
2.Difference between LINQ and nHibernate
S.No LINQ nHibernate
1 LINQ is not an open-source nHibernate is an open source.
2 LINQ is an incomplete ORM tool nHibernate is an ORM tool
as it needs additional extensions.
3 LINQ is primarily a querying nHibernate has a limited querying
language language.
4 LINQ is much more useful in nHibernate is much more useful in
small applications where there is largel applications where there is
no massive dependence on massive dependence on databases.
databases.
5 With LINQ, database already With nHibernate, database does not
exists and the relationships and already exist and it needs to be defined
some programming will be .
dependent on how the database is
defined.

47. 3.Difference between LINQ and Entity Framework
S.No LINQ Entity Framework
1 Used for Rapid Application Used for Enterprise Development
Development
2 Works with objects in database Works with Conceptual model of
database
3 Mainly woks with SQL Server Works with all data sources
4 ".dbml" is created while using ".EDMX" is created while using Entity
LINQ to SQL Framework