Dot.NET/C#/VB.NET/ASP.

NET Interview Questions

Interview Tips .::. DotNet/C#/ASP.Net Questions .::. C/C++/VC.Net Questions.::.
Database/SQL Questions
1. Does C# support multiple inheritance?

No, use interfaces instead

2. What’s the implicit name of the parameter that gets passed into the class’ set method?

Value, and its datatype depends on whatever variable we’re changing

3. What’s the top .NET class that everything is derived from?

System.Object.

4. How’s method overriding different from overloading?

When overriding, you change the method behavior for a derived class. Overloading simply
involves having a method with the same name within the class.

5. What is CLR?

The .NET Framework provides a runtime environment called the Common Language
Runtime or CLR (similar to the Java Virtual Machine or JVM in Java), which handles the
execution of code and provides useful services for the implementation of the program. CLR
takes care of code management at program execution and provides various beneficial services
such as memory management, thread management, security management, code verification,
compilation, and other system services. The managed code that targets CLR benefits from
useful features such as cross-language integration, cross-language exception handling,
versioning, enhanced security, deployment support, and debugging.

6. What is CTS?

Common Type System (CTS) describes how types are declared, used and managed in the
runtime and facilitates cross-language integration, type safety, and high performance code
execution.

7. What is CLS?

The CLS is simply a specification that defines the rules to support language integration in
such a way that programs written in any language, yet can interoperate with one another,
taking full advantage of inheritance, polymorphism, exceptions, and other features. These
 rules and the specification are documented in the ECMA proposed standard document,
"Partition I Architecture", http://msdn.microsoft.com/net/ecma

8. What is strong name?

A name that consists of an assembly's identity—its simple text name, version number, and
culture information (if provided)—strengthened by a public key and a digital signature
generated over the assembly.

9. What is Application Domain?

The primary purpose of the AppDomain is to isolate an application from other applications.
Win32 processes provide isolation by having distinct memory address spaces. This is
effective, but it is expensive and doesn't scale well. The .NET runtime enforces AppDomain
isolation by keeping control over the use of memory - all memory in the AppDomain is
managed by the .NET runtime, so the runtime can ensure that AppDomains do not access
each other's memory. Objects in different application domains communicate either by
transporting copies of objects across application domain boundaries, or by using a proxy to
exchange messages.

10. What is serialization in .NET? What are the ways to control serialization?

Serialization is the process of converting an object into a stream of bytes. Deserialization is

the opposite process of creating an object from a stream of bytes.
Serialization/Deserialization is mostly used to transport objects (e.g. during remoting), or to
persist objects (e.g. to a file or database).Serialization can be defined as the process of storing
the state of an object to a storage medium. During this process, the public and private fields
of the object and the name of the class, including the assembly containing the class, are
converted to a stream of bytes, which is then written to a data stream. When the object is
subsequently deserialized, an exact clone of the original object is created. Binary serialization
preserves type fidelity, which is useful for preserving the state of an object between different
invocations of an application. For example, you can share an object between different
applications by serializing it to the clipboard. You can serialize an object to a stream, disk,
memory, over the network, and so forth. Remoting uses serialization to pass objects "by
value" from one computer or application domain to another. XML serialization serializes
only public properties and fields and does not preserve type fidelity. This is useful when you
want to provide or consume data without restricting the application that uses the data.
Because XML is an open standard, it is an attractive choice for sharing data across the Web.
SOAP is an open standard, which makes it an attractive choice. There are two separate
mechanisms provided by the .NET class library - XmlSerializer and
SoapFormatter/BinaryFormatter. Microsoft uses XmlSerializer for Web Services, and uses
SoapFormatter/BinaryFormatter for remoting. Both are available for use in your own code.

11. What are Satellite Assemblies?

 Satellite assemblies are often used to deploy language-specific resources for an application.
These language-specific assemblies work in side-by-side execution because the application
has a separate product ID for each language and installs satellite assemblies in a language-
specific subdirectory for each language. When uninstalling, the application removes only the
satellite assemblies associated with a given language and .NET Framework version. No
core .NET Framework files are removed unless the last language for that .NET Framework
version is being removed.

12. What is Global Assembly Cache (GAC) and what is the purpose of it?

Each computer where the common language runtime is installed has a machine-wide code
cache called the global assembly cache. The global assembly cache stores assemblies
specifically designated to be shared by several applications on the computer. You should
share assemblies by installing them into the global assembly cache only when you need to.

13. What is Reflection in .NET?

All .NET compilers produce metadata about the types defined in the modules they produce.
This metadata is packaged along with the module (modules in turn are packaged together in
assemblies), and can be accessed by a mechanism called reflection. The System.Reflection
namespace contains classes that can be used to interrogate the types for a module/assembly.

14. What is the managed and unmanaged code in .net?

The .NET Framework provides a run-time environment called the Common Language
Runtime, which manages the execution of code and provides services that make the
development process easier. Compilers and tools expose the runtime's functionality and
enable you to write code that benefits from this managed execution environment. Code that
you develop with a language compiler that targets the runtime is called managed code; it
benefits from features such as cross-language integration, cross-language exception handling,
enhanced security, versioning and deployment support, a simplified model for component
interaction, and debugging and profiling services

15. What are Namespaces?

The namespace keyword is used to declare a scope. This namespace scope lets you organize
code and gives you a way to create globally-unique types. Even if you do not explicitly
declare one, a default namespace is created. This unnamed namespace, sometimes called the
global namespace, is present in every file. Any identifier in the global namespace is available
for use in a named namespace. Namespaces implicitly have public access and this is not
modifiable.

16. What are the access-specifiers available in c#?

 Private, Protected, Public, Internal, Protected Internal.

17. Advantage of ADO.Net?

• ADO.NET Does Not Depend On Continuously Live Connections

• Database Interactions Are Performed Using Data Commands
• Data Can Be Cached in Datasets
• Datasets Are Independent of Data Sources
• Data Is Persisted as XML
• Schemas Define Data Structures

18. Difference between OLEDB Provider and SqlClient ?

SQLClient .NET classes are highly optimized for the .net / sqlserver combination and
achieve optimal results. The SqlClient data provider is fast. It's faster than the Oracle
provider, and faster than accessing database via the OleDb layer. It's faster because it
accesses the native library (which automatically gives you better performance), and it was
written with lots of help from the SQL Server team.

19. Differences between dataset.clone and dataset.copy?

Clone - Copies the structure of the DataSet, including all DataTable schemas, relations, and
constraints.Does not copy any data
Copy - Copies both the structure and data for this DataSet.

20. In a Webservice, need to display 10 rows from a table. So DataReader or DataSet is best
choice?

WebService will support only DataSet.

21. What is Remoting?

The process of communication between different operating system processes, regardless of

whether they are on the same computer. The .NET remoting system is an architecture
designed to simplify communication between objects living in different application domains,
whether on the same computer or not, and between different contexts, whether in the same
application domain or not.

22. What’s the difference between System.String and System.StringBuilder classes?

System.String is immutable; System.StringBuilder was designed with the purpose of having a

 mutable string where a variety of operations can be performed.

23. What’s a delegate?

A delegate object encapsulates a reference to a method. In C++ they were referred to as

function pointers.

24. What’s an interface class?

It’s an abstract class with public abstract methods all of which must be implemented in
the inherited classes

25. What is the transport protocol you use to call a Web service

SOAP is the preferred protocol.