VB .NET Interview Question and answers
1. Explain about visual basic?
Ans: 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.
2. Describe about Visual basic.NET?
ANS: Visual Basic .NET is an object-oriented computer programming language that can be viewed as an evolution of the classic Visual Basic (VB), which is implemented on the .NET Framework.
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.
3. What are the various open source tool available for VB.NET?
Ans: 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.
4. Explain about the performance of Visual basic?
Ans: Visual basic 5 and 6 are efficient in coding the code to native or P-code depending upon the programmer. Portability is a major addition to the performance of VB.NET and the code is also small. Additional layer is provided which interprets the code and this can be avoided by using special algorithms and native code programming.
5. Explain about Visual basic.NET culture?
Ans: VB was always a RAD tool and it was always user friendly for any type of user whether professional or not. It also provided many users with shortcuts and features which made this language popular among many users. It had its share of debugging and maintenance issues of course.
6. Name the method in VB.NET used to define a controls color?
ANS: RGB ()
7. What is Optional Explicit in VB. NET?
ANS: When a variable is assigned with Option Explicit the variable must and should be declared.
Use Option Explicit to avoid incorrectly typing the name of an existing variable or to avoid confusion in code where the scope of the variable is not clear. If you do not use the Option Explicit statement, all undeclared variables are of Object type.
8. What is Project Compatibility in VB6?
ANS: With this setting, VB will generate new interface ID’s for classes whose interfaces have changed, but will not change the class ID’s or the type library ID.
9. Compare C# and Visual basic.NET?
Ans: .NET Frame work includes two languages which are language to IL compilers and in this C# and VB.NET are provided. The importance and flexibility of these as better programming languages is still questionable.
Visual basic has been updated and revised to make it object oriented whereas C# has concepts from many languages such as Delphi, Java, etc and syntax from C and Java.
10. What are types of compatibility in VB6?
ANS: There are three possible project compatibility settings:
11. Define what is Jagged Array in VB.NET?
ANS: Jagged array is multidimensional arrayjagged array is two dimensional it also contain a table where each row can have a different number of columns.
A jagged array is really an array of arrays. To create a jagged array, you declare the array of arrays with multiple sets of parentheses or brackets and indicate the size of the jagged array in the first set of brackets.
12. What is Data Type conversion in VB.NET?
ANS: Convert one variable type to another one is called datatype conversion we can also caleed this casting in VB.NET some automatically conversion is also there.
13. What do u mean by Redim in VB.NET?
ANS: In vb.net we use Redim and erase to manipulate Array. Once we declare an array the size set to array its makes limited to that range but with the help of redim we used to change the array size.
14. What is branching logic control in vb.net?
ANS: Function and subroutines are the answer. The difference in two of them is function sends information back from where it is called means function can return a value but subroutines can not do this.
15: Difference between direct cast and ctype?
ANS: Direct Cast requires the run-time type of an object variable to bet he same as the specified type. The run-time performance of Direct Cast is better than that of C Type, if the specified type and the run-time type of the expression are the same.
C type works fine if there is a valid conversion defined between the expression and the type.
16. Difference between VB6 and VB.Net
* VB.net is object oriented
* VB.Net can be used in Managed Code
* It supports inheritance, implements
* Powerful Exception handling mechanism
* Have support for the console based applications
* More than one version of dll is supported
* Supports the Disconnected data source by using Dataset class
* Supports threading
17. What are the various open source tool available for VB.NET?
ANS: Development of tools for VB has been slow. Mono development platform is one which is implementing VB libraries and is working on a compiler.
18. Advantages of migrating to VB.NET?
ANS: You can create multithreaded, scalable applications using explicit multithreading. A Visual Basic user, can access classes, components, and objects from other CLS-compliant programming languages without worrying about language-specific differences such as data types.
19. What are Data Types?
ANS: Visual Basic .NET introduces three new data types.
The Char data type is an unsigned 16-bit quantity used to store Unicode characters.
The Short data type, a signed 16-bit integer, was named Integer in earlier versions of Visual Basic.
The Decimal data type is a 96-bit signed integer scaled by a variable power of 10. In earlier versions of Visual Basic, it was available only within a Variant.
20. What are attributes in Visual Basic .NET?
ANS: Attributes are items that hold information about items we are using in VB.NET. They are used when VB.NET needs to know more than what standard syntax can specified. Attributes are enclosed in angle brackets<>.
You can also use an attribute like <Attribute> or pass it’s value to a parameter as you can do with procedures like <Attribute (“hello”)>.
21. What for “MustInherit “keyword is used in VB.net?
ANS: If we want to create an Abstract class in VB.net we use MustInherrit keyword. If a class is being a MustInherrit class we can use that class only when it is inherited.