VB.Net Interview Question and Answers

VB.Net Interview Question and Answers

1       What is VB.NET?

VB.Net is a windows based programming language.It supports oops concept.

2.	What is the base class of .net?
	System.Object

3.	What is Difference between Namespace and Assembly?
	Namespace is a collection of different classes. whereas an assembly is the basic building blocks of the .net framework.

4.	What is the difference between early binding and late binding?
	Calling a non-virtual method, decided at a compile time is known as early binding. Calling a virtual method (Pure Polymorphism), decided at a runtime is known as late binding.

5.	What is Intermediate Langauge?
	Microsoft Intermediate Language(MSIL or IL) is the CPU -independent instruction set into which .Net framework programs are compiled. It contains instructions for loading, storing initializing, and calling methods on objects.

6.	What is Commom Language Runtime?
	CLR also known as Common Language Run time provides a environment in which program are executed, it activate object, perform security check on them, lay them out in the memory, execute them and garbage collect them.

7.	What is Common Type System?
	The common type system is a rich type system, built into the common language runtime, which supports the types and operations found in most programming languages.

8.	What is Common Language Specification?
	The Common Language Specification is a set of constructs and constraints that serves as a guide for library writers and compiler writers.
9.	What’s the difference between private and shared assembly?
	Private assembly is used inside an application only and does not have to be identified by a strong name. Shared assembly can be used by multiple applications and has to have a strong name.

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

11.	What is an Assembly?
	Assembly are the basic buiding blocks of the .net framework.They are the logical grouping of the functionality in a physical file.

12.	What are the advantages of an assembly?
	Increased performance. Better code management and encapsulation. It also introduces the n-tier concepts and business logic.

13.	What is Code Access Security?
	CAS - Code Access Security is the part of the .NET security model that determines whether or not a piece of code is allowed to run, and what resources it can use when it is running.

14.	What are the difference between Structure and Class?
	§  Structures are value type and Classes are reference type §  Structures can not have constructors or destructors. §  Classes can have both constructors and destructors. §  Structures do not support Inheritance, while Classes support Inheritance.

15.	What is the differences between dataset.clone and dataset.copy?
	Dataset.clone copies just the structure of dataset (including all the datatables, schemas, relations and constraints.); however it doesn’t copy the data. Dataset.copy, copies both the dataset structure and the data.

16.	What is the use of Internal keyword?
	Internal keyword is one of the access specifier available in .Net framework , that makes a type visible in a given assembly , for e.g : a single dll can contain multiple modules.
17.	What is the difference between the Debug class and Trace class?
	Use Debug class for debug builds, use Trace class for both debug and release builds.

18.	What are class access modifiers?
	Access modifiers are keywords used to specify the declared accessibility of a member or a type. This section introduces the four access modifiers : §  Public §  Protected §  Internal §  Protected inertnal §  Private

19.	What is portable executable?
	The file format used for executable programs and for files to be linked together to form executable programs.

20.	What is 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.

21.	What is tracing?
	Tracing refers to collecting information about the application while it is running. You use tracing information to troubleshoot an application.

22.	What is the difference between a Thread and a Process?
	A Process is an instance of an running application. And a thread is the Execution stream of the Process. A process can have multiple Thread.

23.	What is serialization?
	Serialization is the process of converting an object into a stream of bytes. De-serialization is the opposite process of creating an object from a stream of bytes. Serialization/De-serialization is mostly used to transport objects.

24.	How a base class method is hidden?
	Hiding a base class method by declaring a method in derived class with keyword new. This will override the base class method and old method will be suppressed.
25.	What is a Constructor?
	A special Method Always called whenever an instance of the class is created.

26.	What is Polymorphism?
	Mean by more than one form. Ability to provide different implementation based on different number / type of parameters.

27.	What is an Interface?
	An interface has no implementation; it only has the signature or in other words, just the definition of the methods without the body.

28.	What is the difference between an EXE and a DLL?
	Dll is an In-Process Component whereas EXE is an OUt-Process Component.Exe is for single use whereas you can use Dll for multiple use. Exe can be started as standalone where dll cannot be.

29.	What is the GAC?
	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 that are to be shared by several applications on the computer. This area is typically the folder under windows or winnt in the machine.

30.	How does CAS work?
	The CAS security policy revolves around two key concepts - code groups and permissions. Each .NET assembly is a member of a particular code group, and each code group is granted the permissions specified in a named permission set.