What to create	Quiz
Which subject	Computer science
What age group	Year or Grade 11
What topic	Java - data types, compound assignment, method signature, class, object instantiation
Question types	Close-ended
Number of questions	25
Number of answers	4
Correct answers	Exactly 1
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Computer Science Quiz: Java Basics for Grade 11

Instructions

Please read each question carefully and choose the correct answer from the options provided.

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Questions

1. What is the default value of a boolean variable in Java?

   • A. true
   • B. false
   • C. null
   • D. 0

2. Which of the following is NOT a valid data type in Java?

   • A. int
   • B. float
   • C. char
   • D. real

3. What does a compound assignment operator do in Java?

   • A. Combines multiple variable declarations
   • B. Assigns a value to a variable without changing it
   • C. Allows for operations to be performed and assigned in one statement
   • D. Creates a new variable type

4. Which of the following is the correct method signature for a method that returns an integer and takes no parameters?

   • A. int method()
   • B. method() int
   • C. int method(void)
   • D. void int method()

5. What is an object in Java?

   • A. A class itself
   • B. A reference to a variable
   • C. An instance of a class
   • D. A function within a class

6. Which keyword is used to create a class in Java?

   • A. new
   • B. class
   • C. object
   • D. create

7. What is the purpose of the 'this' keyword in Java?

   • A. It indicates the end of a method
   • B. It refers to the current object instance
   • C. It creates a new class
   • D. It invokes the superclass constructor

8. What will be the output of the following code snippet: int a = 5; a += 3;?

   • A. 5
   • B. 8
   • C. 3
   • D. 6

9. How do you instantiate an object of the class named 'Car'?

   • A. Car myCar = new Car();
   • B. myCar = Car();
   • C. Car myCar();
   • D. new Car myCar;

10. Which data type can store a single character in Java?

    • A. String
    • B. char
    • C. int
    • D. float

11. What keyword is used to define a method in a Java class?

    • A. function
    • B. method
    • C. void
    • D. def

12. *In Java, the compound assignment operator `=` is used for what purpose?**

    • A. Division
    • B. Multiplication and assignment
    • C. Subtraction
    • D. Addition

13. If a variable is declared as String str;, what is its default value?

    • A. ""
    • B. "null"
    • C. null
    • D. undefined

14. What does the following method signature indicate: public void displayInfo()?

    • A. It returns an integer and takes no parameters.
    • B. It returns nothing and takes no parameters.
    • C. It takes parameters and returns void.
    • D. It takes no parameters and returns void.

15. Which of the following statements correctly follows the rules of object-oriented programming?

    • A. Methods can be defined outside of a class.
    • B. Classes can directly access private variables of other classes.
    • C. Objects are created based on classes.
    • D. A class can only contain variables.

16. What is a class in Java?

    • A. A blueprint for creating objects
    • B. A type of variable
    • C. A built-in data type
    • D. A specific function in programming

17. Which of the following keywords indicates that a method can be overridden?

    • A. final
    • B. static
    • C. abstract
    • D. public

18. What will the following code print? System.out.println(10 + 20 + " Hello");

    • A. 30 Hello
    • B. 10 Hello
    • C. Hello 30
    • D. 10 20 Hello

19. What is the result of int x = 10; x -= 3; in Java?

    • A. 10
    • B. 3
    • C. 7
    • D. 13

20. What type of variable is declared with the static keyword?

    • A. Instance variable
    • B. Class variable
    • C. Local variable
    • D. Global variable

21. How can you describe an instance variable?

    • A. It is shared among all objects.
    • B. It belongs to a specific object.
    • C. It cannot be accessed from within the class.
    • D. It is a constant value.

22. In Java, which data type would you use to represent a decimal number?

    • A. int
    • B. double
    • C. char
    • D. boolean

23. In the context of Java, what does encapsulation mean?

    • A. Preventing access to certain components of a class
    • B. The use of external libraries
    • C. The process of compiling code
    • D. The identification of errors in code

24. Which of the following is the correct way to declare an array of integers in Java?

    • A. int[] arr;
    • B. int arr[];
    • C. Both A and B
    • D. Integer arr[10];

25. What is the return type of a method declared as public int calculate()?

    • A. void
    • B. int
    • C. double
    • D. String

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Correct Answers

1. B
2. D
3. C
4. A
5. C
6. B
7. B
8. B
9. A
10. B
11. C
12. B
13. C
14. B
15. C
16. A
17. C
18. A
19. C
20. B
21. B
22. B
23. A
24. C
25. B