MCQs on Basic Input/Output | Lua

1. Using print() for Output

1. What does the print() function in Lua do?
   • a) Reads input from the user
   • b) Displays output to the screen
   • c) Writes data to a file
   • d) Terminates the program
2. Which of the following is a valid syntax to use print()?
   • a) print("Hello, World!")
   • b) echo("Hello, World!")
   • c) display("Hello, World!")
   • d) log("Hello, World!")
3. What will print("Lua", "is", "fun") output?
   • a) Lua is fun
   • b) Lua,is,fun
   • c) Lua is fun (with spaces in between)
   • d) Error: Multiple arguments not allowed
4. Can print() display numbers?
   • a) No, it only works with strings
   • b) Yes, numbers are automatically converted to strings
   • c) Yes, but requires manual conversion
   • d) Only if formatted
5. What happens when you use print() without arguments?
   • a) It throws an error
   • b) It prints a blank line
   • c) It prints nil
   • d) It prints undefined
6. Which function is used to print formatted output in Lua?
   • a) printf()
   • b) format()
   • c) io.write()
   • d) print()
7. What is the difference between print() and io.write()?
   • a) print() adds a newline; io.write() does not
   • b) io.write() adds a newline; print() does not
   • c) Both add a newline by default
   • d) Neither adds a newline
8. Is it possible to print tables directly using print()?
   • a) Yes, it prints the table contents
   • b) No, it prints the memory address
   • c) Yes, but only for numerical keys
   • d) No, it throws an error
9. What does print("Lua", nil, "is great") output?
   • a) Lua is great
   • b) Lua nil is great
   • c) Lua is great (skipping nil)
   • d) Error: Cannot print nil
10. Can print() handle concatenated strings?
    • a) Yes, using + operator
    • b) Yes, using .. operator
    • c) Yes, using both + and ..
    • d) No, concatenation is not supported

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2. Reading Input with io.read()

11. What is the purpose of io.read()?
    • a) To print data to the console
    • b) To read input from the user
    • c) To write data to a file
    • d) To format strings
12. Which function reads a single line of input in Lua?
    • a) read()
    • b) io.input()
    • c) io.read("*l")
    • d) get_line()
13. What happens if io.read() is used without any arguments?
    • a) Reads the entire file
    • b) Reads a single line
    • c) Reads a single word
    • d) Waits for user input
14. What does io.read("*n") do?
    • a) Reads a number from the user
    • b) Reads a newline character
    • c) Reads a string
    • d) Reads multiple lines
15. Which of the following is true about io.read("*a")?
    • a) It reads a single word
    • b) It reads a single line
    • c) It reads all remaining input
    • d) It reads a number
16. Can io.read() handle input redirection from a file?
    • a) No, it only works with the console
    • b) Yes, with io.input()
    • c) No, it requires io.open()
    • d) Yes, without additional configuration
17. What is the default input stream for io.read()?
    • a) The console (stdin)
    • b) A file specified by the user
    • c) The stdout stream
    • d) None of the above
18. How do you close the input stream after using io.read()?
    • a) io.close()
    • b) io.flush()
    • c) input.close()
    • d) It automatically closes
19. What happens if io.read("*n") is used but the user enters a string?
    • a) It reads the string
    • b) It throws an error
    • c) It returns nil
    • d) It reads the first character
20. Can io.read() read multiple inputs at once?
    • a) Yes, using io.read("*l", "*n")
    • b) Yes, with a loop
    • c) No, it only reads one input at a time
    • d) No, requires separate function calls

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3. String Formatting Basics

21. Which function is used to format strings in Lua?
    • a) string.format()
    • b) io.format()
    • c) printf()
    • d) str.format()
22. How do you format numbers with two decimal places in Lua?
    • a) string.format("%.2n", num)
    • b) string.format("%.2f", num)
    • c) format(num, 2)
    • d) format("0.2", num)
23. What does string.format("%s", "Lua") return?
    • a) Lua
    • b) %s Lua
    • c) string
    • d) Error
24. What does the format specifier %d represent in Lua?
    • a) A decimal number
    • b) A floating-point number
    • c) A string
    • d) A date
25. Which format specifier is used for hexadecimal numbers?
    • a) %h
    • b) %x
    • c) %o
    • d) %b
26. How do you format a string with a width of 10 spaces?
    • a) %10s
    • b) %10c
    • c) %s10
    • d) %-10s
27. What happens if more arguments are passed to string.format() than needed?
    • a) It throws an error
    • b) Extra arguments are ignored
    • c) It concatenates them
    • d) It adds placeholders automatically
28. Which of the following is a valid example of formatted output?
    • a) string.format("%d + %d = %d", 2, 3, 5)
    • b) printf("%d + %d = %d", 2, 3, 5)
    • c) io.write("%d + %d = %d", 2, 3, 5)
    • d) log("%d + %d = %d", 2, 3, 5)
29. Can string.format() be used for padding with zeros?
    • a) No
    • b) Yes, using %0nd
    • c) Yes, using %zd
    • d) Only for strings
30. How do you left-align text using string.format()?
    • a) %-s
    • b) %-10s
    • c) %10s
    • d) %<s

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Answers

Qno	Answer
1	b) Displays output to the screen
2	a) print("Hello, World!")
3	c) Lua is fun (with spaces in between)
4	b) Yes, numbers are automatically converted to strings
5	b) It prints a blank line
6	d) print()
7	a) print() adds a newline; io.write() does not
8	b) No, it prints the memory address
9	b) Lua nil is great
10	b) Yes, using .. operator
11	b) To read input from the user
12	c) io.read("*l")
13	d) Waits for user input
14	a) Reads a number from the user
15	c) It reads all remaining input
16	b) Yes, with io.input()
17	a) The console (stdin)
18	a) io.close()
19	c) It returns nil
20	b) Yes, with a loop
21	a) string.format()
22	b) string.format("%.2f", num)
23	a) Lua
24	a) A decimal number
25	b) %x
26	a) %10s
27	b) Extra arguments are ignored
28	a) string.format("%d + %d = %d", 2, 3, 5)
29	b) Yes, using %0nd
30	b) %-10s