VB .NET INTERVIEW QUESTION ANSWER

1. What is Metadata?

Metadata is termed as “Data about content of the data” and it is found in the catalog of libraries. Practically, it is used at back side of book to see the necessary topic.

2. What is the difference between VB and VB.Net?

Following are the differences between VB and VB.Net:

VB	VB.Net
Platform dependent	Platform Independent
VB is backward compatible	VB.Net is not backward compatible
Interpreted	Compiler Language
Exception Handling by ‘On Error…..Goto’	Exception Handling by ‘Try….Catch’
Cannot develop multi-threaded applications	Can develop multi thread applications

 

3. What is namespace?

    A namespace is an organized way of representing Class, Structures and interfaces present in .NET language. Namespaces are hierarchically structured index of a class library, available to all .NET Languages.               

4. Which namespace are used for accessing the data? 

System.Data namespace is used for accessing and managing data from the required data source. This namespace deals only with the data from the specified database. 

5. What is JIT?

    JIT is termed as Just in Time compiler which is used as a part of runtime execution environment. There are three types of JIT and they are:

• Pre-JIT – Compiles at the time of deployment of an application
• Econo-JIT – Compiles called methods at runtime
• Normal JIT – Compiles called methods at runtime and they get compiled first time when called.

6. What is an assembly and its use?

    An assembly is one of the elements of a .NET application and it termed as a primary unit of all .NET applications. This assembly can be either DLL or executable file.

7. What is strong name in .NET assembly?

Strong Name is an important feature of .Net and it is used to identify shared assembly uniquely. Strong name has solved the problem of creating different object with same name and it can be assigned with the help of Sn.exe.

8. What are the different types of assembly?

There are two types of assembly –

• Private – A private assembly is normally used by a single application and it is stored in application’s directory.
• Public – A public assembly or shared assembly is stored in Global Assembly Cache(GAC) which can be shared by many applications 

9. What is the difference between Namespace and Assembly?

Assembly is physical grouping of all units and Namespace logically groups classes. Namespace can have multiple assemblies.

10. What are the various open source tool available for VB.NET?

When compared with the rapid development of open source tools for other languages from Microsoft (C#, etc) we can say that development of tools for VB has been slow. Mono development platform is one which is implementing VB libraries and is working on a compiler.

 11. Describe about Visual basic.NET?

 This is used in conjunction with Microsoft .NET platform and is a successor to visual basic sixth version. Visual basic is used in conjunction with.NET Framework. This tool has a serious defect it is not compatible with Microsoft visual basic sixth version. It has a huge library which assists programmers.

12. Explain and brief about rapid application development tool?

Rapid action development tool describes about the software development process. This tool gives flexibility in iterative development and prototype deployment. It enhances the speed of application development. It is also used for application maintenance.

 13 . Explain about .NET?

NET is a Microsoft Framework and a software component. .NET has a large library of pre-coded solutions which provided developer significant help in developing applications with solutions already present. It offers reliable security and cross platform compatibility.

14.Explain about visual basic?

Visual basic is associated with the IDE of Microsoft. It is basically useful to implement RAD of GUI. Creation of Active X scripts are very easy and efficient through VB. Windows API can also be used to create application on windows desktop and its applications. This was primarily designed to create applications for windows platform.

15. What is jagged array in VB.Net?

 Jagged array is nothing but an array of arrays. Each entry in the array is another array that can hold any number of items.

16. What is Manifest?

A Manifest is a text file that is used to store metadata information of .NET assemblies. File type of Manifest can be saved as a type PE. Assembly Name, Version, Culture and key token can be saved as a Manifest.

17. What are all the differences between Dispose and Finalize()?

Finalize method is called by Garbage collector which helps us to make free of unmanaged resources. There are some other resources like window handles, database connections are handled by iDisposable interface.

Dispose method is handled by IDisposable interface to explicitly release unused resources. Dsipose can be called even if other references to the object are alive.

18. What is Garbage Collection?

Garbage collection is also known as automatic memory management, which is used for automatic recycling of dynamically allocated memory. Garbage collection is performed by Garbage collector which will recycle memory if it is proven that memory will be unused.

19. What are the types of generations in garbage collector?

There are three types of generations in garbage collector.

Generation 0 – This identifies a newly created object that has been never marked for collection.

Generation 1 – This identifies an object which has been marked as collection but not removed.

Generation 2 – This identifies an object that has survived more than one sweep of the Garbage collector.

20. What is the use of Option explicit?

Variable must be compulsorily declared when the Option Explicit is termed as ON. If it is OFF, variables can be used without declaration.

21. What is the difference between int and int32?

Int32 represent 32-bit signed integer whereas int is not a keyword used in VB.Net. 

22. What is hashtable?

Hashtable is set to be items with key and value pairs. Keys are referred as indexes and quick search can be performed for values by searching through the keys.

23. What are nested classes?

A class that can be declared within the scope of another class. These classes are considered within the scope of the enclosed class and are available within that class or scope.

24. What is Enumerator?

An Enumerator or Enum is a value type with a set of constants given to the set of the list. Enumeration is used when definition is required for more than one number.

25. What is Delegate?

A delegate is defined as an object that can refer to a method. Whenever a delegate is assigned to a method, it behaves exactly like that method.

Example:

public delegate int performaddition(int z, int b);

26. What is Globalization?

Globalization is nothing but making the application  Internationalize and localizing the application to other languages or cultures. Culture is nothing but a combination of Language(English) and the location like US or UK.

 27. What is the difference between value and reference types?

Value types directly store the data and it is allocated to stack. Reference type store a reference to the value’s memory address and are allocated to heap.

28. What is TRACE in VB.Net?

TRACE allows the user to view how the code has been executed in detail. This tells how the code is working.

29. What is Authentication and Authorization?

Authentication is the process of obtaining credentials from the users and verifying the user’s identity. Authorization is the process of giving access to the authenticated resources. Authentication leads to Authorization.

30. What are the types of Authentication?

There are three types of Authentication and they are –

• Windows Authentication
• Forms Authentication
• Passport Authentication

31. What is Global Assembly Cache (GAC)?

GAC is used where shared .NET assembly resides. It is used in the following criteria:

• If .Net assembly has special security requirements
• If .Net application has to be shared with other applications