Vb.net exam questions and answers
Here are 20 VB.NET exam questions along with their answers:
What is VB.NET?
Answer: VB.NET is a programming language developed by Microsoft that is based on the Visual Basic programming language.
What is the difference between VB.NET and Visual Basic?
Answer: VB.NET is an evolution of the Visual Basic language and includes additional features and improvements over the previous versions.
What is a variable in VB.NET?
Answer: A variable in VB.NET is a named storage location that holds a value of a particular data type.
What is the scope of a variable in VB.NET?
Answer: The scope of a variable determines its accessibility or visibility within the program. It can be declared at the module level, procedure level, or block level.
What is the difference between ByVal and ByRef in VB.NET?
Answer: ByVal is used to pass arguments by value, meaning that the original value is copied to a new memory location, while ByRef is used to pass arguments by reference, allowing changes to the original value.
How do you declare a constant in VB.NET?
Answer: Constants are declared using the "Const" keyword followed by the constant name and value. For example, "Const Pi As Double = 3.14159".
What are the different control structures in VB.NET?
Answer: VB.NET supports control structures such as If-Then-Else, Select Case, For loop, Do-While loop, Do-Until loop, and While loop.
What is the difference between a function and a subroutine in VB.NET?
Answer: A function returns a value, while a subroutine does not. Functions are called using their name and can be used in expressions, whereas subroutines are called using their name and perform a series of statements.
How do you handle exceptions in VB.NET?
Answer: Exceptions are handled using the Try-Catch-Finally block. The code that may raise an exception is placed in the Try block, and the Catch block handles the exception if one occurs. The Finally block is optional and is used to specify code that will always execute, regardless of whether an exception occurred.
What is the purpose of the "Imports" statement in VB.NET?
Answer: The "Imports" statement is used to create an alias for a namespace or to import a namespace so that you don't have to fully qualify the names of types in that namespace.
What is the difference between a class and an object in VB.NET?
Answer: A class is a blueprint or template for creating objects, while an object is an instance of a class.
What is inheritance in VB.NET?
Answer: Inheritance is a feature that allows a class to inherit properties, methods, and other members from another class. It promotes code reuse and helps in creating a hierarchy of related classes.
How do you declare an array in VB.NET?
Answer: Arrays in VB.NET can be declared using the "Dim" keyword followed by the array name and the number of elements. For example, "Dim numbers(5) As Integer".
How do you sort an array in VB.NET?
Answer: You can use the Array.Sort() method to sort an array in VB.NET. For example, "Array.Sort(numbers)".
What is the purpose of the "Me" keyword in VB.NET?
Answer: The "Me" keyword refers to the current instance of the class and is used to access its properties, methods, and events.
How do you read data from a file in VB.NET?
Answer: You can use the StreamReader class to read data from a file in VB.NET. First, create an instance of the StreamReader class and then use its methods, such as ReadLine or ReadToEnd, to read the contents of the file.
How do you write data to a file in VB.NET?
Answer: You can use the StreamWriter class to write data to a file in VB.NET. First, create an instance of the StreamWriter class and then use its methods, such as Write or WriteLine, to write data to the file.
What is the purpose of the "Handles" keyword in VB.NET?
Answer: The "Handles" keyword is used to associate an event with an event handler in VB.NET. It allows the event handler to respond to a specific event raised by a control or object.
How do you connect to a database in VB.NET?
Answer: You can connect to a database in VB.NET using ADO.NET. First, create a connection object and specify the connection string with the necessary database details. Then, open the connection and execute queries or commands using a data adapter or command object.
What is the difference between a module and a class in VB.NET?
Answer: A module is a container for code that can include variables, methods, and properties, similar to a class. However, unlike a class, you cannot create instances of a module. It is typically used for organizing utility functions or global variables.
Conclusion:
These questions and answers cover various aspects of VB.NET programming and can serve as a good starting point for exam preparation. Make sure to study further and practice coding to deepen your understanding of the language and its concepts.
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