Top 50+ VB.Net Interview Questions and Answers for 2025

Top VB.Net Interview Questions and Answers

1. State the difference between Vb and Vb.Net.

Vb: Vb is considered to be platform dependent and is backward compatible. It can’t develop multi-threaded applications and can do exception handling by ‘On Error…Goto’.

Vb.Net: Vb.Net is platform-independent and is capable of building multi-threaded applications. It is not backward compatible and has exception handling by ‘Try…Catch’.

2. Define Namespace.

It is considered a more aligned way of highlighting Classes, Structures, and interfaces included in the .NET language. It is hierarchically structured and available to all the .NET Languages.

3. Define NameSpaces used for accessing the data.

One can use System. Data namespace for accessing and managing data from the respective source. The primary use of this Namespace is to deal with the data only from the specified database.

4. What do you mean by JIT?

JIT, known as Just In Time Compiler, can be used as a runtime execution environment. One can identify three types of JIT:

1. Pre-JIT: It is compiled at the deployment stage of an application.
2. Econo- JIT: It calls methods at runtime.
3. Normal JIT: It compiles and calls a method at runtime, which gets compiled instantly when called.

5. How do you define assembly and its usage of it?

Assembly is considered one of the elements of the .NET application. It is also known as the primary unit among all .NET Applications. It can be identified as DLL or Executable File.

6. What are the different types of assembly?

Assembly can be identified into two types: Private and Public

1. Private: It is used by a single application and can be stored in the application’s directory.
2. Public: This is stored in Global Assembly Cache (GAC) and can be shared by several applications.

7. State the difference between Namespace and Assembly?

Assembly is considered the physical grouping of all the units. However, Namespace is known for logically grouping the classes. The Namespace can have multiple assemblies, unlike assembly.

8. How do you define the INTERNAL keyword?

INTERNAL is known as one of the access specifiers. It is usually visible in a given assembly known as DLL File. It accumulates a single binary component and can be figured out throughout the assembly.

9. Define Option Strict?

Option Strict Keyword saves data from getting lost while the implicit data gets converted. It ensures compile time notification of such types of conversions.

10. How do you define Option Explicit?

It is the keyword used in a file to declare all the variables. This can be done using declared keywords like Dim, Public, Private and Protected. 

11. Mention the use of New Keyword?

New Keyword can be used either as a modifier or an operator along with the constructor. It can hide inherited members from the base class if used as a modifier. However, it is efficient for creating an object to invoke constructors if used as an operator.

12. What is a Jagged Array?

A jagged Array is defined as an array of arrays. Every Array entry is considered another array capable of holding an end number of items. 

13. How do you Manifest?

It is a text file that can store metadata info of .NET assemblies. The file that includes Manifest can be saved as type PE. Be it Assembly Name, Version, Culture, or Keytoken: these can be saved as a Manifest.

14. Define the difference between Dispose and Finalize()?

Garbage Collector considers the finalize method to keep us free from unmanageable resources. Some of the resources are managed by iDisposable Interface. Those resources are window handles and database connections.

Dispose the iDisposable Interface controls method. It is used to release unused resources. 

15. Define Garbage Collection?

This is also considered automatic memory management. It is utilized for the automatic recycling of allocated memory. This collection is performed by a Garbage collector that is capable of recycling the memory if it is unused. 

16. Identify the types of generations in Garbage Collector?

One can identify three types of generations in the Garbage Collector.

Generation 0: It is considered a newly curated object, never marked for collection.

Generation 1: The one marked as a collection but not evaded.

Generation 2: One that has survived more than one sweep of the overall Garbage Collector.

17. How do we use Option Explicit?

If the Option Explicit is ON, then the Variable should be declared. However, if it is OFF, all the variables can be used without declaration.

18. Define the difference between int and int32?

Int32 is defined as a 32-bit signed integer. It is not considered a keyword in VB.Net.

19. Define Hashtable?

It is a set of items with key and value pairs. Keys are known as indexes. One can quickly search for values if done rightly through the keys.

20. Define Deep Copy?

It is known as curtains a new object and then copying the non-static fields of the present object to a new one. 

21. How can one store decimal data in .NET?

One can use BinaryWriter to store the decimal data in .NET.

22. Define strong typing and weak typing?

Strong type is used to check the types of variables when compiling. However, the Weak type is used to check the types of Systems at a later stage which is also the run time. 

23. State the number of classes that DLL can contain?

DLL can contain the end number of classes.

24. State the difference between thread and process?

One can use Thread to execute more than one program in a particular period. However, Process executes one program at a time.

25. Define the two significant parts of .NET?

The two main parts of .NET are Common Language Runtime (CLR) and .NET Framework Class Library.

26. State the languages supported by .NET?

The languages are C#, VB.NET, Perl, and COBOL.

27. Define Serialization in .Net?

It is the process of converting an object to a stream of bytes. It is mainly used to transport objects.

28. Define CLS?

CLS is known as Common Language Specification, a subset of CTS. It is utilized to unite all the languages under one umbrella.

29. How do you define CTS?

It is known as the Common Type System used to communicate efficiently between the languages. 

30. Specify the difference between Value and Reference Type?

Value is allocated to the stack and directly stores the data. Reference Type preserves a reference to the value’s memory address. It is earmarked to the heap.

31. What is Metadata?

Metadata is data that provides information about other data. It’s a set of data that describes and provides information about other data. 

• It helps document and organize stored data to be easily accessed and used. 
• It can include the name, size, type of file, where it was created, the date it was designed, who made it, and how it’s linked to other files. 

Any given data set would be much more challenging to comprehend and access without metadata. 

32. What is the difference between C# and VB.Net?

The significant difference between C# and VB.Net is that C# is a statically typed language, but VB.Net is a dynamically typed language. These definitions mean that in C#, variables must be declared with a specific data type, while in VB.Net, variables can be expressed without a data type. 

These differences make C# more robust, as it can enforce stricter rules on data use. However, because of this, C# can be more challenging, as beginners must learn about data types before starting programming.

33. What is a strong name in .NET assembly?

A strong name is a name that is unique to an assembly. It consists of the assembly's identity—its simple name, version number, and culture information (the public key and a digital signature). Strong names guarantee that an assembly is truly unique and allows side-by-side installation of multiple versions of an assembly in the Global Assembly Cache (GAC).

34. What are ReDim keywords and their use?

The ReDim keyword is used in Visual Basic to resize an array. It allows the programmer to reduce or increase the number of elements in an array by re-declaring the array with a different number of elements. This ReDim keyword can only be used on fixed-size or static arrays, not dynamic ones. ReDim preserves the contents of the array during the resize operation unless the number and size of the elements changes. 

The following example shows how to use the ReDim keyword to resize an array:

1. Dim MyArray() As Integer
2. ReDim MyArray(10)

In the above example, the MyArray array is declared with no size. The ReDim keyword is then used to resize the array to 10 elements. 

35. What is the difference between System.String and System.StringBuilder classes?

• System.String is an immutable class, meaning you cannot modify the string objects once created. System.StringBuilder is a mutable class, meaning you can adjust the string builders after the creation.
• System.String is the best usage option when you know a string will not need to be modified after it is created. On the other hand, system.StringBuilder is the best usage option when a string needs to be modified after it is created.

36. What are nested classes?

Nested classes are classes that are defined inside another class and are also known as inner classes. They have been used to logically group classes together and to create more readable and maintainable code. They are often used for group-related functionality or to provide an inner class implementation that is more convenient than a traditional static nested class. Nested classes can also access all members of their outer class, including private members. 

37. What is an Enumerator?

An enumerator is a type of data structure that allows for the efficient storage and retrieval of data elements. Enumerators are often used to store data sets too large to fit into memory or are accessed frequently. While using an enumerator, the data set will be divided into smaller chunks, each stored in a separate location. The enumerator then keeps track of the location of each piece and can quickly retrieve the desired data element by indexing it into the appropriate location.

38. What is Delegate?

A delegate is a type of object that refers to a method or a function. The delegate object references the method or functions to execute it. For example, delegates can pass methods as arguments to other methods, define callback methods and implementations of events, and implement code asynchronously.

39. What is Globalization?

Globalization is designing and developing software applications that can adapt to diverse languages, cultures, and regions. It is the process of internationalizing software so customers and businesses worldwide can use it. By implementing globalization features, software applications can recognize and display multiple languages, currencies, time zones, and other regional settings. Globalization is crucial for businesses that operate in various regions, as it allows them to deliver a localized experience to their customers.

40. What is the difference between Dataset and Datareader?

Dataset and DataReader are two objects used to read data from a data source. 

• The main difference between the two is that a DataReader is a read-only, forward-only data stream. At the same time, a DataSet is an in-memory data cache that can be manipulated and persisted. 
• Additionally, Datareader is faster than a DataSet, as it reads data directly from the data source.

41. What is TRACE in VB.Net?

TRACE is a built-in function in VB.Net that writes text to the Output window at design time and runtime. It is used for recording and displaying the progress of an application at runtime. In addition, it is constructive for debugging, as it allows developers to view their programs' actions at each step and ensure that the program behaves as expected. Trace messages can be output to the Output window, a text file, or the Immediate window.

42. What are Authentication and Authorization?

• Authentication is the process of verifying a user's identity, but authorization is the process of determining what resources a user is allowed to access. 
• Authentication is the first step in a two-step process. Authorization is the second step in determining a user's actions on a given resource.

43. What are the types of authentication?

There are three main types of authentication:

1. Single-factor authentication
2. Two-factor authentication
3. Multi-factor authentication.

• Single-factor authentication is the most basic type and only requires a single piece of evidence, such as a password, to gain access.
• Two-factor authentication is more secure than single-factor authentication, as it requires two pieces of evidence, such as a password and a fingerprint, to gain access.
• Multi-factor authentication is the most secure type, as it requires three or more pieces of evidence, such as a password, a fingerprint, and an iris scan, to gain access.

44. What is the Global Assembly Cache (GAC)?

The Global Assembly Cache (GAC) is a machine-wide code cache that stores .NET assemblies which are specifically designated to be shared by several applications on the computer. Therefore, assemblies deployed in the GAC must have a solid name.

45. What is CLR?

CLR stands for Common Language Runtime. It is a virtual machine component of the Microsoft .NET framework that provides a runtime environment for the execution of programs written in a .NET language, such as C# and Visual Basic. NET. 

CLR is responsible for managing the execution of .NET programs, providing services such as memory management, type safety, exception handling, garbage collection, security, and thread management.

46. What is the Managed code?

Managed code is a programming code that targets a virtual machine, such as the Common Language Runtime (CLR) in the .NET Framework. Managed code takes advantage of services provided by the Common Language Runtime, such as memory management and security. Managed code can be written in any language compiler that targets the Common Language Runtime, such as Visual Basic, C#, and Visual C++.

47. What is the difference between Convert.tostring and i.tostring method?

The Convert.ToString() method is a static method that converts a data type to a string data type. It can convert any data type, including objects, to a string.

The I.ToString() method is an instance method that returns the object's string representation. In addition, it will return the fully qualified type name of the object unless the object itself has overridden it.

48. How many .NET languages can a single .NET DLL contain?

A single .NET DLL can contain multiple .NET languages. This affordability is because the .NET Framework is language-agnostic, meaning it can run code in any .NET language. As a result, a single .NET DLL can have code written in multiple .NET languages, making it a powerful tool for developers.

49. What class allows an element to be accessed using a Unique key?

The class that allows an element to be accessed using a unique key is called the Primary Key class. This class is responsible for keeping track of the element's unique key to retrieve later. 

For example, when an element is added to the database, the PrimaryKey class generates a unique key. Then this key is used to access the element when it is needed.

50. What is Code Security?

Code security is a broad term that encompasses a range of practices and techniques used to protect source code from unauthorized access and modification. It can include practices such as code encryption, code obfuscation, code signing, code access control, and other techniques. Code security aims to protect the intellectual property and integrity of source code and prevent malicious individuals from manipulating source code for their benefit.

51. Which DLL is used for Microsoft .NET run time?

The answer to this question depends on which version of the Microsoft .NET Framework you use. For example, if you are using the .NET Framework 4, then the answer is that the mscoree.dll file is used for the Microsoft .NET runtime. However, another DLL file is needed for the runtime if you use a different version of the .NET Framework.

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Conclusion

Starting your career as a programmer or software engineer is the most challenging yet exciting decision. If you want to start your journey today and crack the interview with flying colors, then you should certainly consider these VB.Net interview questions. 

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