Latest Dot Net Interview Questions

Latest Dot Net Interview Questions Book

2011-08-19T08:10:00.000-07:00

Dot Net Interview Questions Book 6th Edition is written By Shiv Prasad Koirala. He is working in MNC and has good Experience in Software Fields.

The Following Topics are covered in this Books.

Top 50 Technical and Non-technical Questions

.Net Framework and .Net Interoperability

Threading & Remoting and Web Services

ASP.Net, ASP.NET 2.0, .Net 3.5 and ATLAS-AJAX

Caching Concepts, OOPS and.Net Architecture

ADO.Net & SQL Server, XML, Reports

Localization and Globalization & Project Management

Windows Communications and Foundations,Windows Presentation Framework and Windows Workflow Foundation

Sample Address Application Projects.

The book has more than 500 questions in Dot Net. The book Covers .Net 1.0, 1.1, 2.0,3.0, 3.5. 4.0

The Book is specially for Dot Net Developers who is looking for job. if you go through this book, you will get more confidence. Dot Net Interview Questions For Fresher and Experienced.

Dot Net Project Idea for Final Year Student

2011-08-15T04:43:00.000-07:00

Here I am giving Some Project idea for Final Year Students. Final Year Project Ideas for B.Tech & MCA.

You can choose which Technology you want to do (VB.Net, C#.Net, ASP.Net, SQL Server, Oracle, MySQL, and XML)

Final Year MCA/ M.Sc./ B.Tech/ B.E/ M.Tech Project Idea :

    School Management System

    College Manaegement System

    Online Tutoring System

    Human Resource Management System

    Mobile Ticket Reservation System

    Purchase Order System

    Online Recruitment systems

    Online Quiz System

    Real estate application softwares

    Leave management system

    Online Polling System

    Internet Banking System

    Online survey tool

    Recipe management system

    Meeting Scheduler System

    Online Test System

You can choose you want to do Web application or Window applications. if you want any Dot Net Projects idea, Post your Comments with email id. we will send you.

Dot Net Projects for Final Year MCA Students Bangalore, Dot Net Projects for Final Year B. Tech. Students Bangalore, Dot Net Projects for Final Year B.E. Students Bangalore, Dot Net Project for Final Year Students Bangalore.

Mca Final year, Dot Net Project Idea, Final Year Project Idea. New and Latest Dot Net Project Ideas, Computer Project Ideas, Engineering Project, Science Fair Project Ideas, School Projects. Advanced Concept in Dot Net Projects

Advanced Interview Question in Dot Net

2011-08-07T12:02:00.000-07:00

Here I am giving Advanced Dotnet Interview Questions. You should know about WPF, WCF, Design Patterns, N Tier Architecture, Generics and Fundamentals of .Net FrameWork.

1. Explain about Generics?

2. In Assembly which work as GacBrowser ?

3. What are the consideration in deciding to use .NET Remoting or ASP.NET Web Services?

4. Describe the Provider Model in ASP.NET 2.0?

5. What do you mean by three-tier architecture?

6. Does .NET CLR and SQL SERVER run in different process?

7. The IHttpHandler and IHttpHandlerFactory interfaces ?

8. When not to use Design Patterns

9 . When to use Design Patterns

10 . Benefits of Design Patterns

11. What are Design Patterns?

12. What is difference between WCF and Web Services

13. What is Difference between WPF and Windows Forms.

14. What is WCF?

15. What is WPF?

if you are going for interview , Please prefer well. 3 + Years Experience Interview Questions.
Advanced Interview Question in Dot Net, Interview questions, Asp.Net Interview Questions, ASP.Net, ASP.Net 2.0, ASP.Net 3.5, ASP.Net 4.0,3 + Years Experience Interview Questions

How to improve SQL Server Performance

2011-08-07T10:43:00.000-07:00

I am giving some points to improve the SQL Server Performance.If you want to improve your application performance, you want to improve your SQL Server Performance also.

1. Don' t use Select * from tablename. Use SELECT ColumnName FROM tablename instead of it.

Example : Use below Query

SELECT EmpName FROM EmpDetails.

2. Don't use Lower Case in SQL Server statements,

Example : Don't use : select ColumnName from tablename.
Use Upper case : SELECT EmpName FROM EmpDetails.

3. Don't use "IN", "NOT IN" , "DISTINCT" in your query. if not required .

4. Don't use "Cross Join" if not required

5. Don't use Having Clause if not required .

6. Don't use Cursor if not required

It is very important for increase the performance of the SQL Server.

If you want to improve your SQL Server, you need follow the above tips.

It will help you.

I will add some more point in SQL Server Performance. Thanks for spending your valuable time.
if you have any doubts or any suggestion, Post your comments.

State Management Questions

2011-07-24T09:50:00.005-07:00

State Management Questions

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

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

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

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

Web Service Questions

2011-07-24T09:49:00.000-07:00

Web Service Questions

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

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

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

4. Where on the Internet would you look for Web services?
http://www.uddi.org

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

Web Control Class in ASP.Net 4.0

2011-07-24T09:29:00.000-07:00

Few Basic Standard Control included in the WebControl Class :

Button Control
CheckBox Control
Label Control
Textbox Control
FileUpload Control
Image Control
ImageButton Control
RadioButton Control

I will explain this control (Web Control Class in ASP.Net 4.0) later

SQL Server Interview questions

2010-01-15T00:07:00.001-08:00

This section will contain SQL Server Interview Questions and Answers.

1. How to optimize stored procedures in SQL Server?
Ans: I. Use where clause
II. Select only required fields
III. Do join on indexed key fields

2. What is the difference between Stored procedure and User defined functions?

3. Why should we go for Stored Procedures? Why not direct queries?
Ans: SP are precompiled and contain an execution plan with it. Hence, they are faster.

4. How many NULL values we can have in a Unique key field in SQL Server?
Ans: Only one. In case of Oracle, we can have multiple NULL values in a Unique key field.

5. What is correlated subquery?
6. What is an index. What are the types?

Indexes in databases are very much similar to Indexes in Books. Indexes help in searching data faster.

Types: Clustered Index
Non-Clustered Index

7. What is the difference between a clustered index and a non-clustered index?

Clustered:
1 Only one clustered index allowed per table
2 Physically rearranges the data
3 For use on columns that are frequently searched for range of data

Non-clustered:
1 Upto 249 non-clustered index allowed per table
2 Doesn’t rearrange the data. Keeps a pointer to the data.
3 For use on columns that are searched for single value.

8. What is a join? What are the types of joins?

Joins are used to retrieve data from multiple tables.

Following are the types of joins:
Inner join
Left outer join
Right outer join
Full outer join
Cross join
9. What is a transaction?

A SQL transaction is a sequence of operations performed as a
single unit of work. If all the tasks are completed successfully, then the transaction is committed (saved). If a single task fails, the transaction is rolled back (discarded).

10. What is ACID property of transaction?

A SQL transaction must exhibit ACID property, i.e Atomicity, Consistency, Isolation, and Durability.

Atomicity: A transaction is always treated as a single unit of work, i.e. either all the tasks are performed or none of them, no intermediate stage.
Consistency: When a transaction is completed, it must leave all datain a consistent state. Isolation: Modifications made by a transaction must be isolated from the modifications made by other transactions. Durability: After a transaction is completed, it’s effects are permanently in place in the system.

11. What is SET NOCOUNT ON?

When we perform a SELECT, INSERT, UPDATE or DELETE query, it returns a COUNT (number of rows affected) when SET NOCOUNT OFF. If SET NOCOUNT ON, it doesn’t return the COUNT.

12. How to delete exactly duplicate records from a table?

There are many ways. Simplest answer is:
i. Let the table tab1 contains duplicate records.
ii. Insert distinct records from tab1 in a temporary table #temp
INSERT INTO #temp
SELECT DISTINCT * FROM tab1
iii. Delete all rows from original table tab1
DELETE FROM tab1
iv. Insert from temporary table
INSERT INTO tab1
SELECT * FROM #temp
Try other solutions yourself.

13. How to get nth highest salary from employee table.

The query below demonstrates how to find the 5th highest salary. Replace 5 with any integer to get nth salary.

SELECT TOP 1 SALARY
FROM (SELECT DISTINCT TOP 5 SALARY
FROM EMPLOYEE ORDER BY SALARY DESC) a
ORDER BY SALARY ASC

Please post your comments here. Also, post your questions to get an answer.

What is the use of indexes and what are the types of indexes available in SQL Server?

2010-01-14T23:45:00.000-08:00

What is the use of indexes and what are the types of indexes available in SQL Server?
Indexes are used to find data quickly when a query is processed in any relational database. Indexes improve performance by 10 to 500 times.
Index can improve the performance in following operations:

* Find the records matching with WHERE clause

UPDATE Books SET Availability = 1 WHERE SubjectId =12
DELETE FROM Books WHERE Price <10
SELECT * FROM Books WHERE Price BETWEEN 50 AND 80
* Sorting the result with ORDER BY

SELECT * FROM Books ORDER BY Price DESC
* Grouping records and aggregate values

SELECT Count(*) as Units, Price FROM Books GROUP BY Price

There are two types of indexes available in SQL Server: clustered and non-clustered
Clustered index
Clustered index physically reorders the records of a table. Therefore a table can have only one clustered index. Usually a clustered index will be created on the primary key of a table.
Non – Clustered Index
Non – Clustered index are stored in the order of the index key values, but the information in the table is stored in a different order. Means logical sorting of data not Physical. In SQl Server 2005 a table can have 249 non-clustered indexes.
Composite Indexes
A composite index is an index on two or more columns. Both clustered and non-clustered indexes can be composite indexes. If you have composite index on Price and BookName then take can take advantage of it like this:
SELECT BookName, Price FROM Products ORDER BY UnitPrice BookName, Price DESC

What is static member of class?

2010-01-14T23:44:00.003-08:00

What is static member of class?

A static member belongs to the class rather than to the instances of the class. In C# data fields, member functions, properties and events can be declared static. When any instances of the class are created, they cannot be used to access the static member.
To access a static class member, use the name of the class instead of an instance variable
Static methods and Static properties can only access static fields and static events.

Like: int i = Car.GetWheels;
Here Car is class name and GetWheels is static property.

Static members are often used to represent data or calculations that do not change in response to object state.

What is a static class?

2010-01-14T23:44:00.001-08:00

What is a static class?
We can declare a static class. We use static class when there is no data or behavior in the class that depends on object identity. A static class can have only static members. We can not create instances of a static class using the new keyword. .NET Framework Common Language Runtime (CLR) loads Static classes automatically when the program or namespace containing the class is loaded.

Here are some more features of static class

* Static classes only contain static members.
* Static classes can not be instantiated. They cannot contain Instance Constructors
* Static classes are sealed.

What is the basic functionality of Garbage Collector in Microsft.Net?

2010-01-14T23:43:00.002-08:00

The Common Language Runtime (CLR) requires that you create objects in the managed heap, but you do not have to bother with cleaning up the memory once the object goes out of the scope or is no longer needed. The Microsoft .NET Framework Garbage Collector provides memory management capabilities for managed resources. The Garbage Collector frees objects that are not referenced and reclaims their memory. You should set your references to Nothing(null) as soon as you are done with them to ensure your objects are eligible for collection as soon as possible.
Here are the list of some tasks performed by the Garbage collector:

* Garbage collector reserves a piece of memory as the application starts for the managed heap.
* Garbage collector controls the managed heap memory currently used and available to an application.
* Garbage collector allocates memory for new objects within the application.
* The Garbage Collector attempts to reclaim the memory of objects that are not referenced.

Explain ACID properties of the database?

2010-01-14T23:43:00.001-08:00

All Database systems which include transaction support implement ACID properties to ensure the integrity of the database. ACID stands for Atomicity, Consistency, Isolation and Durability

* Atomicity: Each transaction is said to be “atomic.” If one part of the transaction fails, the entire transaction fails. Modifications on the data in the database either fail or succeed.

* Consistency: This property ensures that only valid data will be written to the database. If, for some reason, a transaction is executed that violates the database’s consistency rules, the entire transaction will be rolled back and the database will be restored to a state consistent with those rules.

* Isolation: It requires that multiple transactions occurring at the same time not impact each other’s execution.

* Durability: It ensures that any transaction committed to the database will not be lost.

What is the use of XSLT?

2010-01-14T23:42:00.002-08:00

What is the use of XSLT?

XSLT stands for Extensible Stylesheet Language Transformations. This language used in XSL style sheets to transform XML documents into other XML documents.

XSLT is based on template rules which specify how XML documents should be processed. An XSLT processor reads both an XML document and an XSLT style sheet. Based on the instructions the processor finds in the XSLT style sheet, it produce a new XML document. With XSLT we can also produce HTML or XHTML from XML document. With XSLT we can add/remove elements and attributes, rearrange and sort elements, hide and display elements from the output file. Converting XML to HTML for display is probably the most common application of XSLT today.

What is a Strong Name in Microsoft Visual Studio.Net?

2010-01-14T23:42:00.001-08:00

What is a Strong Name in Microsoft Visual Studio.Net?
In Microsoft Visual Studio.Net a strong name consists of the assembly's identity. The strong name guarantees the integrity of the assembly. Strong Name includes the name of the .net assembly, version number, culture identity, and a public key token. It is generated from an assembly file using the corresponding private key.
Steps to create strong named assembly:

To create a strong named assembly you need to have a key pair (public key and a private key) file.

Use sn -k KeyFile.snk

Open the dot net project to be complied as a strong named assembly. Open AssembyInfo.cs/

AssembyInfo.vb file. Add the following lines to AssemblyInfo file.

[Assembly: AssemblyVersion("1.0.*")]

[assembly: AssemblyDelaySign(false)]

[assembly: AssemblyKeyFile("..\\..\\KeyFile.snk")]

Compile the application, we have created a strong named assembly.

What is the difference between classes and structs in Microsoft.Net?

2010-01-14T23:39:00.001-08:00

What is the difference between classes and structs in Microsoft.Net?

# A struct is a value type, while a class is a reference type.

# When we instantiate a class, memory will be allocated on the heap. When struct gets initiated, it gets memory on the stack.

# Classes can have explicit parameter less constructors. But structs cannot have this.

# Classes support inheritance. But there is no inheritance for structs. A struct cannot inherit from another struct or class, and it cannot be the base of a class. Like classes, structures can implement interfaces.

# We can assign null variable to class. But we cannot assign null to a struct variable, since structs are value type.

# We can declare a destructor in class but can not in struct.

What is the purpose of Connection Pooling in ADO.NET?

2010-01-14T23:38:00.001-08:00

What is the purpose of Connection Pooling in ADO.NET?
Connection pooling enables an application to use a connection from a pool of connections that do not need to be re-established for each use. Once a connection has been created and placed in a connection pool, an application can reuse that connection without performing the complete connection creation process.

By default, the connection pool is created when the first connection with a unique connection string connects to the database. The pool is populated with connections up to the minimum pool size. Additional connections can be added until the pool reaches the maximum pool size.

When a user request a connection, it is returned from the pool rather than establishing new connection and, when a user releases a connection, it is returned to the pool rather than being released. But be sure than your connections use the same connection string each time. Here is the Syntax

conn.ConnectionString = "integrated Security=SSPI; SERVER=192.168.0.123; DATABASE=MY_DB; Min Pool Size=4;Max Pool Size=40;Connect Timeout=14;";

Explain the Delegates in C#.

2010-01-14T23:36:00.002-08:00

Delegates in C# are objects which points towards a function which matches its signature. Delegates are reference type used to encapsulate a method with a specific signature. Delegates are similar to function pointers in C++; however, delegates are type-safe and secure.
Here are some features of delegates:

* A delegate represents a class.
* A delegate is type-safe.
* We can use delegates both for static and instance methods
* We can combine multiple delegates into a single delegate.
* Delegates are often used in event-based programming, such as publish/subscribe.
* We can use delegates in asynchronous-style programming.
* We can define delegates inside or outside of classes.

Syntax of using delegates

//Declaring delegate
delegate void SampleDelegate(string message);

// declare method with same signature:
static void SampleDelegateMethod(string message) { Console.WriteLine(message); }

// create delegate object
SampleDelegate d1 = SampleDelegateMethod;

// Invoke method with delegate
d1("my program");

Value types VS Reference types C#

2010-01-14T23:36:00.001-08:00

What is difference between Value types and Reference types in VB.NET or C# (Value types VS Reference types)

C# provides two types—class and structure, class is a reference type while the other is a value type. Here is difference between Value types and Reference types.

Value types directly contain their data which are either allocated on the stack or allocated in-line in a structure. Reference types store a reference to the value's memory address, and are allocated on the heap. With reference types, an object is created in memory, and then handled through a separate reference—rather like a pointer.

Reference types can be self-describing types, pointer types, or interface types. Primitive types such as int, float, bool and char are value types.

Variables that are value types each have their own copy of the data, and therefore operations on one variable do not affect other variables. Variables that are reference types can refer to the same object; therefore, operations on one variable can affect the same object referred to by another variable.

Value types have a default implied constructor that initializes the default value. Reference types default to a null reference in memory.

Value types derive from System.ValueType. Reference types derive from System.Object.

Value types cannot derive a new type from an existing value type, except for structs. Reference types can derive a new type from an existing reference type as well as being able to implement interfaces.

SQL Server 2008 advantages for Developers

2010-01-14T23:35:00.002-08:00

Microsoft has released a new version of its popular Database management system (SQL Server). It is Microsoft SQL Server 2008. So what are the benefits of SQL SERVER 2008 for Developers & Programmers.

SQL Management Studio improvements including IntelliSense.

New Data Types for just dates or times (no more storing time when you only need the date).

New Hierarchical data support .IsDescendent(), that can automatically pull a hierarchical view of data (no more custom recursive queries).

New Grouping Sets statement which enables you to automatically group dimensions in a query for easy aggregation and reporting.

New Merge statement which provides automatic insert/update semantics for keeping multiple data sources in sync.

New data types and support for Geodata and geometry.

New support for optimizing "empty" or row/column tables using the sparse keyword.

New FileStream attribute that enables you to include files that are stored in the server file system, but can be managed by SQL Server.

SQL Server Basic Databases

2010-01-14T23:35:00.001-08:00

SQL Server Interview Question. Name the Basic or Default Databases of SQL SERVER and What are their functions and use.?

Microsoft SQL SERVER Provides 4 default databases

The Master database holds information for all databases located on the SQL Server instance and is the glue that holds the engine together. Because SQL Server cannot start without a functioning master database, you must administer this database with care.

The tempdb holds temporary objects such as global and local temporary tables and stored procedures. The model is essentially a template database used in the creation of any new user database created in the instance.

The msdb database stores information regarding database backups, SQL Agent information, DTS packages, SQL Server jobs, and some replication information such as for log shipping.

Aggregate Functions in SQL SERVER 2008

2010-01-14T23:34:00.001-08:00

What are Aggregate functions? Explain Aggregate functions in SQL SERVER 2008 with example.

Aggregate functions are applied to a group of data values from a column. Aggregate functions always return a single value.

SQL SERVER 2008 / Transact-SQL supports following aggregate functions:

AVG: Calculates the arithmetic mean (average) of the data values contained within a column. The column must contain numeric values.

MAX and MIN: Calculate the maximum and minimum data value of the column, respectively. The column can contain numeric, string, and date/time values.

SUM: Calculates the total of all data values in a column. The column must contain numeric values.

COUNT: Calculates the number of (non-null) data values in a column. The only aggregate function not being applied to columns is COUNT(*). This function returns the number of rows (whether or not particular columns have NULL values).

COUNT_BIG: New and Analogous to COUNT, the only difference being that COUNT_BIG returns a value of the BIGINT data type.

Aggregate function Example:
SELECT ProjectName, SUM(budget) TotalBudget FROM Project_Tbl GROUP BY ProjectName;

Dot Net Inteview Questions -V

2009-12-16T20:59:00.001-08:00

I have added Few Asp.Net Interview Questions and Answer

Q81. What technique is used to figure out that the page request is a postback?
Ans. The IsPostBack property of the page object may be used to check whether the page request is a postback or not. IsPostBack property is of the type Boolean.

Q82. Which event of the ASP.NET page life cycle completely loads all the controls on the web page?
Ans. The Page_load event of the ASP.NET page life cycle assures that all controls are completely loaded. Even though the controls are also accessible in Page_Init event but here, the viewstate is incomplete.

Q83. How is ViewState information persisted across postbacks in an ASP.NET webpage?
Ans. Using HTML Hidden Fields, ASP.NET creates a hidden field with an ID="__VIEWSTATE" and the value of the page's viewstate is encoded (hashed) for security.

Q84. What is the ValidationSummary control in ASP.NET used for?
Ans. The ValidationSummary control in ASP.NET displays summary of all the current validation errors.

Q85. What is AutoPostBack feature in ASP.NET?
Ans. In case it is required for a server side control to postback when any of its event is triggered, then the AutoPostBack property of this control is set to true.

Q86. What is the difference between Web.config and Machine.Config in .NET?
Ans. Web.config file is used to make the settings to a web application, whereas Machine.config file is used to make settings to all ASP.NET applications on a server(the server machine).

Q87. What is the difference between a session object and an application object?
Ans. A session object can persist information between HTTP requests for a particular user, whereas an application object can be used globally for all the users.

Q88. Which control has a faster performance, Repeater or Datalist?
Ans. Repeater.

Q89. Which control has a faster performance, Datagrid or Datalist?
Ans. Datalist.

Q90. How to we add customized columns in a Gridview in ASP.NET?
Ans. Make use of the TemplateField column.

Q91. Is it possible to stop the clientside validation of an entire page?
Ans. Set Page.Validate = false;

Q92. Is it possible to disable client side script in validators?
Ans. Yes. simply EnableClientScript = false.

Q93. How do we enable tracing in .NET applications?
Ans. <%@ Page Trace="true" %>

Q94. How to kill a user session in ASP.NET?
Ans. Use the Session.abandon() method.

Q95. Is it possible to perform forms authentication with cookies disabled on a browser?
Ans. Yes, it is possible.

Q96. What are the steps to use a checkbox in a gridview?
Ans.

Q97. What are design patterns in .NET?
Ans. A Design pattern is a repeatitive solution to a repeatitive problem in the design of a software architecture.

Q98. What is difference between dataset and datareader in ADO.NET?
Ans. A DataReader provides a forward-only and read-only access to data, while the DataSet object can carry more than one table and at the same time hold the relationships between the tables. Also note that a DataReader is used in a connected architecture whereas a Dataset is used in a disconnected architecture.

Q99. Can connection strings be stored in web.config?
Ans. Yes, in fact this is the best place to store the connection string information.

Q100. Whats the difference between web.config and app.config?
Ans. Web.config is used for web based asp.net applications whereas app.config is used for windows based applications.
if you want any interview question, post your comments, we will send you.

You can refer following link .Net Interview Question.

Dot Net Inteview Questions -I

Dot Net Inteview Questions -II

Dot Net Inteview Questions -III

Dot Net Inteview Questions -IV

Dot Net Inteview Questions -V

If you have any questions or suggestion, Post your Comments.

Dot Net Inteview Questions -IV

2009-12-16T20:58:00.002-08:00

Q61. Is a delegate a type-safe functions pointer?
Ans. Yes

Q62. What is the return type of an event in .NET?
Ans. There is No return type of an event in .NET.

Q63. Is it possible to specify an access specifier to an event in .NET?
Ans. Yes, though they are public by default.

Q64. Is it possible to create a shared event in .NET?
Ans. Yes, but shared events may only be raised by shared methods.

Q65. How to prevent overriding of a class in .NET?
Ans. Use the keyword NotOverridable in VB.NET and sealed in C#.

Q66. How to prevent inheritance of a class in .NET?
Ans. Use the keyword NotInheritable in VB.NET and sealed in C#.

Q67. What is the purpose of the MustInherit keyword in VB.NET?
Ans. MustInherit keyword in VB.NET is used to create an abstract class.

Q68. What is the access modifier of a member function of in an Interface created in .NET?
Ans. It is always public, we cant use any other modifier other than the public modifier for the member functions of an Interface.

Q69. What does the virtual keyword in C# mean?
Ans. The virtual keyword signifies that the method and property may be overridden.

Q70. How to create a new unique ID for a control?
Ans. ControlName.ID = "ControlName" + Guid.NewGuid().ToString(); //Make use of the Guid class

Q71A. What is a HashTable in .NET?
Ans. A Hashtable is an object that implements the IDictionary interface, and can be used to store key value pairs. The key may be used as the index to access the values for that index.

Q71B. What is an ArrayList in .NET?
Ans. Arraylist object is used to store a list of values in the form of a list, such that the size of the arraylist can be increased and decreased dynamically, and moreover, it may hold items of different types. Items in an arraylist may be accessed using an index.

Q72. What is the value of the first item in an Enum? 0 or 1?
Ans. 0

Q73. Can we achieve operator overloading in VB.NET?
Ans. Yes, it is supported in the .NET 2.0 version, the "operator" keyword is used.

Q74. What is the use of Finalize method in .NET?
Ans. .NET Garbage collector performs all the clean up activity of the managed objects, and so the finalize method is usually used to free up the unmanaged objects like File objects, Windows API objects, Database connection objects, COM objects etc.

Q75. How do you save all the data in a dataset in .NET?
Ans. Use the AcceptChanges method which commits all the changes made to the dataset since last time Acceptchanges was performed.

Q76. Is there a way to suppress the finalize process inside the garbage collector forcibly in .NET?
Ans. Use the GC.SuppressFinalize() method.

Q77. What is the use of the dispose() method in .NET?
Ans. The Dispose method in .NET belongs to IDisposable interface and it is best used to release unmanaged objects like File objects, Windows API objects, Database connection objects, COM objects etc from the memory. Its performance is better than the finalize() method.

Q78. Is it possible to have have different access modifiers on the get and set methods of a property in .NET?
Ans. No we can not have different modifiers of a common property, which means that if the access modifier of a property's get method is protected, and it must be protected for the set method as well.

Q79. In .NET, is it possible for two catch blocks to be executed in one go?
Ans. This is NOT possible because once the correct catch block is executed then the code flow goes to the finally block.

Q80. Is there any difference between System.String and System.StringBuilder classes?
Ans. System.String is immutable by nature whereas System.StringBuilder can have a mutable string in which plenty of processes may be performed.
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2009-12-16T20:58:00.001-08:00

Q41. How to instruct the garbage collector to collect unreferenced data?
Ans. We may call the garbage collector to collect unreferenced data by executing the System.GC.Collect() method.

Q42. How can we set the Focus on a control in ASP.NET?
Ans. txtBox123.Focus(); OR Page.SetFocus(NameOfControl);

Q43. What are Partial Classes in Asp.Net 2.0?
Ans. In .NET 2.0, a class definition may be split into multiple physical files but partial classes do not make any difference to the compiler as during compile time, the compiler groups all the partial classes and treats them as a single class.

Q44. How to set the default button on a Web Form?
Ans.

Q45.Can we force the garbage collector to run?
Ans. Yes, using the System.GC.Collect(), the garbage collector is forced to run in case required to do so.

Q46. What is Boxing and Unboxing?
Ans. Boxing is the process where any value type can be implicitly converted to a reference type object while Unboxing is the opposite of boxing process where the reference type is converted to a value type.

Q47. What is Code Access security? What is CAS in .NET?
Ans. CAS is the feature of the .NET security model that determines whether an application or a piece of code is permitted to run and decide the resources it can use while running.

Q48. What is Multi-tasking?
Ans. It is a feature of operating systems through which multiple programs may run on the operating system at the same time, just like a scenario where a Notepad, a Calculator and the Control Panel are open at the same time.

Q49. What is Multi-threading?
Ans. When an application performs different tasks at the same time, the application is said to exhibit multithreading as several threads of a process are running.2

Q50. What is a Thread?
Ans. A thread is an activity started by a process and its the basic unit to which an operating system allocates processor resources.

Q51. What does AddressOf in VB.NET operator do?
Ans. The AddressOf operator is used in VB.NET to create a delegate object to a method in order to point to it.

Q52. How to refer to the current thread of a method in .NET?
Ans. In order to refer to the current thread in .NET, the Thread.CurrentThread method can be used. It is a public static property.

Q53. How to pause the execution of a thread in .NET?
Ans. The thread execution can be paused by invoking the Thread.Sleep(IntegerValue) method where IntegerValue is an integer that determines the milliseconds time frame for which the thread in context has to sleep.

Q54. How can we force a thread to sleep for an infinite period?
Ans. Call the Thread.Interupt() method.

Q55. What is Suspend and Resume in .NET Threading?
Ans. Just like a song may be paused and played using a music player, a thread may be paused using Thread.Suspend method and may be started again using the Thread.Resume method. Note that sleep method immediately forces the thread to sleep whereas the suspend method waits for the thread to be in a persistable position before pausing its activity.

Q56. How can we prevent a deadlock in .Net threading?
Ans. Using methods like Monitoring, Interlocked classes, Wait handles, Event raising from between threads, using the ThreadState property.

Q57. What is Ajax?
Ans. Asyncronous Javascript and XML - Ajax is a combination of client side technologies that sets up asynchronous communication between the user interface and the web server so that partial page rendering occur instead of complete page postbacks.

Q58. What is XmlHttpRequest in Ajax?
Ans. It is an object in Javascript that allows the browser to communicate to a web server asynchronously without making a postback.

Q59. What are the different modes of storing an ASP.NET session?
Ans. InProc (the session state is stored in the memory space of the Aspnet_wp.exe process but the session information is lost when IIS reboots), StateServer (the Session state is serialized and stored in a separate process call Viewstate is an object in .NET that automatically persists control setting values across the multiple requests for the same page and it is internally maintained as a hidden field on the web page though its hashed for security reasons.

Q60. What is a delegate in .NET?
Ans. A delegate in .NET is a class that can have a reference to a method, and this class has a signature that can refer only those methods that have a signature which complies with the class.

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