MCQs on Basic Input/Output | Visual Basic .NET (VB.NET)

Explore these 30 engaging MCQs to test your knowledge of Basic Input/Output in VB.NET. Covering Console usage, file handling, and output formatting, this quiz helps strengthen your programming basics!

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Using the Console

1. Which method is used to read input from the user in VB.NET?
   • A. Console.Read
   • B. Console.ReadLine
   • C. Console.Write
   • D. Console.WriteLine
2. What does Console.WriteLine do in VB.NET?
   • A. Writes output without a newline
   • B. Writes output with a newline
   • C. Reads input with a newline
   • D. Clears the console
3. Which method is used to clear the console screen?
   • A. Console.Reset
   • B. Console.Clean
   • C. Console.Clear
   • D. Console.Flush
4. What happens if you call Console.ReadLine but no input is provided?
   • A. Throws an exception
   • B. Returns null
   • C. Returns an empty string
   • D. Returns a newline
5. How can you format output directly in a Console.WriteLine statement?
   • A. Using escape sequences
   • B. Using placeholders {}
   • C. Using interpolation $
   • D. Both B and C

Basic File I/O (Read/Write)

6. Which class is used to write text to a file in VB.NET?
   • A. FileStream
   • B. StreamWriter
   • C. TextWriter
   • D. FileWriter
7. What does the File.Create method do?
   • A. Creates and opens a file
   • B. Appends data to a file
   • C. Deletes a file
   • D. Reads a file
8. Which method reads all lines from a text file?
   • A. File.ReadText
   • B. File.ReadLines
   • C. File.ReadAllText
   • D. File.ReadAllLines
9. How do you append data to an existing file?
   • A. File.WriteText
   • B. File.AppendText
   • C. File.AddLine
   • D. File.Create
10. What happens if you write to a file that doesn’t exist?

• A. Throws an error
• B. Creates a new file
• C. Skips the operation
• D. Appends data

11. Which namespace is primarily used for file operations in VB.NET?

• A. System.IO
• B. System.Text
• C. System.Data
• D. System.File

12. What is the purpose of the StreamReader class?

• A. Reading binary files
• B. Reading text from a stream
• C. Writing to a stream
• D. Managing file paths

13. How do you close a StreamWriter after use?

• A. StreamWriter.Close
• B. StreamWriter.Dispose
• C. StreamWriter.Flush
• D. Both A and B

14. What happens if a file is locked when trying to write using StreamWriter?

• A. Overwrites the file
• B. Skips the write operation
• C. Throws an exception
• D. Opens in read mode

15. Which class is used to delete files?

• A. FileStream
• B. File.Delete
• C. FileManager
• D. FileWriter

Formatting Output

16. How do you format a floating-point number to two decimal places in VB.NET?

• A. F2
• B. .ToString("F2")
• C. Format(2)
• D. Round(2)

17. Which method is used to align output in columns?

• A. String.Format
• B. TabAlign
• C. PadLeft/PadRight
• D. Console.Align

18. What is the purpose of the String.Format method?

• A. Concatenates strings
• B. Formats strings
• C. Trims strings
• D. Pads strings

19. How do you represent a percentage in formatted output?

• A. .ToString("%")
• B. .ToString("P")
• C. .Format("%")
• D. .ToString("F%")

20. Which escape sequence is used for a newline in VB.NET?

• A. \n
• B. \r
• C. \t
• D. \l

21. How do you display a currency symbol using formatting?

• A. .ToString("C")
• B. .Format("Currency")
• C. "$" + Value
• D. .ToCurrency()

22. What happens when Console.WriteLine uses {0} as a placeholder?

• A. Throws an error
• B. Formats the string
• C. Outputs a default value
• D. Inserts the first argument

23. How do you include a tab in a formatted string?

• A. "\t"
• B. "Tab"
• C. "\b"
• D. "Space(4)"

24. What is the output of .ToString("D4") for the value 5?

• A. 0005
• B. 005
• C. 5.000
• D. D0005

25. How can you ensure formatted alignment for a table-like display?

• A. String.PadLeft/String.PadRight
• B. String.Trim
• C. Console.AlignTab
• D. Console.RowFormat

26. Which symbol is used for custom numeric format patterns?

• A. $
• B. #
• C. *
• D. &

27. What does the "E" format specifier represent?

• A. Exponential notation
• B. Empty string
• C. Exact decimal
• D. Error

28. Which property of strings is commonly used for trimming output?

• A. .Trim()
• B. .Cut()
• C. .Remove()
• D. .Clean()

29. How do you display negative numbers in parentheses?

• A. ("C")
• B. .ToString("(#)")
• C. .ToString("N0")
• D. .ToString("#,##0.00;(#,##0.00)")

30. How do you round numbers to the nearest integer in VB.NET?

• A. .Round()
• B. .ToInteger()
• C. .ToString("F0")
• D. .RoundInt()

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Answer Key

Qno	Answer (Option with the text)
1	B. Console.ReadLine
2	B. Writes output with a newline
3	C. Console.Clear
4	C. Returns an empty string
5	D. Both B and C
6	B. StreamWriter
7	A. Creates and opens a file
8	D. File.ReadAllLines
9	B. File.AppendText
10	B. Creates a new file
11	A. System.IO
12	B. Reading text from a stream
13	D. Both A and B
14	C. Throws an exception
15	B. File.Delete
16	B. .ToString(“F2”)
17	C. PadLeft/PadRight
18	B. Formats strings
19	B. .ToString(“P”)
20	A. \n
21	A. .ToString(“C”)
22	D. Inserts the first argument
23	A. \t
24	A. 0005
25	A. String.PadLeft/String.PadRight
26	B. #
27	A. Exponential notation
28	A. .Trim()
29	D. .ToString(“#,##0.00;(#,##0.00)”)
30	A. .Round()