Top 50 Java MCQ Questions
17 Jul 2024
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Java MCQs are a good way to practice and become a master in Java programming. Java is a high-level object-oriented programming language. It is easy to understand and used to develop programs. For the preparation of the Java Interview or exam, Java developers and students should go through the multiple choice questions and answers of Java once in a lifetime
So, In this Java tutorial,I brought some multiple choice questions and answers on Java programming language only for you It will help you to prepare well for your exams or interviews. So let's explore the top 50 Java MCQ questions and answers. Let's see one by one
1. Which of these is not a feature of Java?
- A.Object-oriented
- B.Platform-independent
- C.Compiled
- D.Interpreted language
Answer: C Compiled
| Read More: Top 12 Features of Java |
2. Which component of Java is responsible for running the compiled Java bytecode?
- A.JDK
- B.JVM
- C.JRE
- D.JIT
Answer: B.JVM
3. What is the purpose of the PATH environment variable in Java?
- A.To locate Java libraries
- B.To store Java bytecode
- C. To Locate the exe files (.exe)
- D.To optimize Java code
Answer: C. To Locate the exe files (.exe)
4. Which feature of Java makes it possible to run a Java program on different platforms?
- A.Object-Oriented
- B.Platform-Independent
- C.Syntax
- D.Memory Management
Answer: B.Platform-Independent
5. In Java, how should class names be written?
- A.camelCase
- B.snake_case
- C.PascalCase
- D.kebab-case
Answer: C.PascalCase
6. How do I comment on a block of code in Java?
- A./*comment*/
- B.//comment
- C.!--comment--
- D.%comment
Answer: A./*comment*/
7. What is multithreaded programming?
- A. It’s a process in which two different processes run simultaneously
- B. It’s a process in which two or more parts of the same process run simultaneously
- C.It’s a process in which many different process are able to access the same information
- D. It’s a process in which a single process can access information from many sources
Answer: B. Multithreaded programming is a process in which two or more parts of the same process run simultaneously.
8. What is the default value of a boolean variable in Java?
- A.true
- B.false
- C.0
- D.null
Answer: B.false
9. What is the result of this operation in Java?
(int)(7.9) - A.7
- B.7.9
- C.8
- D.Syntax Error
Answer: A.7
10. Which keyword is used to define a constant variable in Java?
- A.final
- B.static
- C.const
- D.immutable
Answer: A.final
11. What is the range of the short data type in Java?
- A.-32768 to 32767
- B.-128 to 127
- C.-2147483648 to 2147483647
- D.0 to 65535
Answer: A.-32768 to 32767
12. What will be the output of the following code snippet?
int a = 10; int b = 20;
System.out.println(a + b);
- A.10
- B.20
- C.30
- D.Error
Answer: C.30
13. Identify the output.
boolean isJavaFun = true; System.out.println(!isJavaFun); - A.true
- B.false
- C.Error
- D.null
Answer: B.false
14. Which one of the following is true for Java
- A. Java is object-oriented and interpreted
- B. Java is efficient and faster than C
- C. Java is the choice of everyone.
- D. Java is not robust.
Answer: A. Java is object-oriented and interpreted
15. What is the output of this pseudocode?
SET x = 10
IF x > 5
THEN PRINT "Greater"
ELSE PRINT "Lesser" - A.Greater
- B.Lesser
- C.Error
- D.No output
Answer: A.Greater
16. Evaluate this pseudocode.
SET a = 3 SET b = 4 PRINT a * b - A.7
- B.12
- C.Error.
- D.None of the above
Answer: B.12
17. Determine the output.
SET num = 4 IF num MOD 2 = 0 THEN PRINT "Even" ELSE PRINT "Odd" A.Even
B.Odd
C.Error
D.No output
Answer: A.Even
18. Identify the error in this code.
int[] nums = new int[2];
nums[0] = 1;
nums[1] = 2;
nums[2] = 3; - A.Array index out of bounds
- B.Incorrect array declaration
- C.No error
- D.Syntax error
Answer: A.Array index out of bounds
19. Spot the mistake in this code snippet.
int i = 0; while(i < 5) { i++; } System.out.println(i); - A.Infinite loop
- B.Syntax error
- C.No error
- D.Prints 0
Answer:C.No error
20. Which control structure is used to execute a block of code multiple times?
- A.if
- B.switch-case
- C.for
- D.try-catch
Answer: C.for
21. What will be the output of the following code snippet.
if(false){ System.out.println("True"); } else{ System.out.println("False"); } - A.True
- B.False
- C.Error
- D.No Output
Answer: B.False
22. In a 'switch-case' statement, what is the role of the 'break' keyword?
- A. To pause the execution
- B. To terminate the case block
- C. To skip to the next case
- D. To repeat the case block
Answer: B.To terminate the case block
23. What is the difference between 'while' and 'do-while' loops in Java?
- A.Syntax only
- B. The 'do-while' loop executes at least once
- C.Execution speed
- D.No difference
Answer:B. The 'do-while' loop executes at least once
24. Which keyword is used to exit a loop prematurely in Java?
- A.break
- B.continue
- C.exit
- D.stop
Answer: A.break
25. What will the following loop print?
for(int i = 0; i < 4; i++)
{
System.out.println(i);
} - A.0 1 2
- B.1 2 3
- C.0 1 2 3
- D.None
Answer: A.0 1 2
26. What is the output of this code?
int x = 1;
while(x < 4)
{
System.out.println(x);
x++;
}
- A.1 2 3
- B.2 3 4
- C.1 2 3 4
- D.1
Answer: A.1 2 3
27. What will this pseudocode output?
SET count = 5
DO PRINT count
COUNTDOWN count
- A.5 4 3 2 1
- B.5
- C.1 2 3 4 5
- D.None
Answer: A.5 4 3 2 1
28. Analyze this pseudocode.
SET num = 0
WHILE num <= 5
IF num MOD 2 = 0
THEN PRINT num END
IF INCREMENT num
- A.0 2 4
- B.0 1 2 3 4 5
- C.2 4
- D.0 2 4 6
Answer: A.0 2 4
29. Identify the error.
for(int i=0; i<=5; i++)
{
System.out.println(i);
}
System.out.println(i);
- A.Syntax error outside the loop
- B.No error
- C.Variable i not accessible outside loop
- D.Infinite loop
Answer: C.Variable i not accessible outside the loop
30. Spot the mistake.
int counter = 0;
while(counter < 5)
{
counter++;
}
System.out.println("Count: " + counter);
- A.Loop never terminates
- B.Counter not incremented
- C.No error
- D.Print statement incorrect
Answer:C.No error
31. Find the error in this code.
int num = 1;
do{
System.out.println(num);
num++;
} while(num <= 3);
System.out.println(num);
- A.Infinite loop
- B.Syntax error
- C.Prints wrong values
- D.No error
Answer:D.No error
32. Which class is commonly used for simple keyboard input in Java?
- A.Scanner
- B.InputStream
- C.BufferedReader
- D.FileReader
Answer: A.Scanner
33. In Java, what is the default value of an array of integers?
- A.0
- B.null
- C.1
- D.-1
Answer: A.0
34. What does 'BufferedReader' in Java provide that 'Scanner' does not?
- A.Faster input reading
- B.Input from file only
- C.Different data types
- D.Graphical interface
Answer: A.Faster input reading
35. How do you access the third element in an array named 'arr'?
- A.arr[2]
- B.arr[3]
- C.arr(2)
- D.arr(3)
Answer:A.arr[2]
36. How do you access the third element in an array named 'arr'?
- A.Compile-time error
- B.Runtime error: ArrayIndexOutOfBoundsException
- C.No error
- D.Logical error
Answer: B.Runtime error: ArrayIndexOutOfBoundsException
37. What is the purpose of the 'length' attribute in a Java array?
- A. To determine the size of the array
- B. To modify the size of the array
- C. To sort the array
- D. To initialize the array
Answer: A.To determine the size of the array
38. Which of these is not a valid way to instantiate an array in Java?
- A.int[] arr = new int[5];
- B.int arr[] = new int[5];
- C.int arr[] = {1, 2, 3, 4, 5};
- D.int arr[] = int[5];
Answer:int arr[] = int[5];
39. In a multi-dimensional array, how do you access the element in the second row and third column of an array named 'matrix'?
- A.matrix[1][2]
- B.matrix[2][3]
- C.matrix[2][2]
- D.matrix[1][3]
Answer:A.matrix[1][2]
40. What will the following code output?
int[] arr = {1, 2, 3};
for(int num : arr)
{
System.out.println(num);
}
- A.1 2 3
- B.123
- C.Error
- D.None
Answer: A.1 2 3
41. What does this Java code do?
int[][] arr = {{1, 2}, {3, 4}};
for(int i = 0; i < arr.length; i++)
{
for(int j = 0; j < arr[i].length; j++)
{
System.out.print(arr[i][j] + " ");
}
System.out.println(); }
- A.Prints a 2D array in matrix form
- B.Prints only the first row of the array
- C.Prints the sum of the array elements
- D.Gives an error
Answer: A.Prints a 2D array in matrix form
42. What will be the result of executing this code snippet?
String[] names = {"Java", "Python", "C++"};
System.out.println(names[1].length());
- A.4
- B.5
- C.6
- D.Error
Answer: C.6
43. Analyze this code.
int[] nums = new int[3];
nums[1] = 10;
int x = nums[1] + nums[0];
System.out.println(x);
- A.0
- B.10
- C.Error
- D.None
Answer: B.10
44. What will this pseudocode output?
SET arr = [1, 2, 3] FOR EACH num IN arr PRINT num
- A.1 2 3
- B.123
- C.Error
- D.None
Answer: A.1 2 3
45. Determine the output of this pseudocode.
SET arr = [10, 20, 30] SET sum = 0 FOR i = 0 TO LENGTH(arr) - 1 INCREMENT sum BY arr[i] PRINT sum
- A.60
- B.1020 30
- C.Error
- D.None
Answer: A.60
46. What will be the result of this pseudocode?
SET matrix = [[1, 2], [3, 4]]
PRINT matrix[0][1]
- A.1
- B.2
- C.3
- D.4
Answer: B.2
47. Identify the issue in this code snippet.
int[] numbers = new int[5];
for(int i = 0;
i <= numbers.length;i++) {System.out.println(numbers[i]);
}
- A.Out of bounds array access
- B.No issue
- C.Syntax error
- D.Logic error
Answer: A.Out-of-bounds array access
48. Spot the mistake in this code.
String[] names = {"Java", "Python", "C"};
for(int i = 0;
i < names.length;
i++) {
System.out.println(names[i].length());
}
- A.Prints incorrect lengths
- B.No error
- C.Syntax error
- D.Logic error
Answer:B.No error
49. Find the error in this Java code.
int[][] matrix = new int[2][2];
matrix[0][0] = 1;
matrix[0][1] = 2;
matrix[1][0] = 3;
System.out.println(matrix[1][1]);
- A.Prints incorrect value
- B.No error
- C.Syntax error
- D.Missing initialization for matrix[1][1]
Answer: D.Missing initialization for matrix[1][1]
50. Identify the flaw in this Java code.
char[] chars = new char[-1];
- A.Negative array size
- B.Syntax error
- C.No error
- D.Logic error
Answer: A.Negative array size
51. Which keyword is used to prevent a class from being subclassed in Java?
- A.static
- B.final
- C. abstract
- D.sealed
Answer: B. final
52. Which of the following is not a Java access modifier?
- A.public
- B.private
- C. protected
- D.package
Answer: D. package
53. Which exception is thrown when a thread is waiting, sleeping, or otherwise occupied, and the thread is interrupted?
- A. InterruptedException
- B.IOException
- C.SQLException
- D.ArithmeticException
Answer: A. InterruptedException
54. Which method must be implemented by all threads in Java?
- A.start()
- B. run()
- C. init()
- D.execute()
Answer: B. run()
55. Which of the following is a checked exception in Java?
- A.NullPointerException
- B.ClassCastException
- C. IOException
- D.ArithmeticException
Answer: C. IOException
56. What is the default value of a local variable in Java?
- A.0
- B.null
- C. Undefined
- D.Compiler error
Answer: D. Compiler error.
57. Which method is used to find the length of a string in Java?
- A.length()
- B.size()
- C.getSize()
- D.getLength()
Answer: A. length()
58. Which operator is used to concatenate two strings in Java?
- A.+
- B. &
- C.&&
- D. ++
Answer: A. +
59. Which of the following is a superclass of every class in Java?
- A.Object
- B.Class
- C. Interface
- D.Super
Answer: A. Object
60. Which of the following methods can be used to start a new thread in Java?
- A. start()
- B.run()
- C.execute()
- D. init()
Answer: A. start()
Conclusion:
Java Multiple Choice Questions (MCQs) and answers are an important resource for testing Java programming expertise. We covered various Java concepts, including multithreading and memory management which will help you in interviews and exams. For a more understanding of Java refer to our Java Certification Program.
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FAQs
Q1. Who is the godfather of Java?
James Gosling is considered the father of Java.
Q2. What is Java full form?
JAVA stands for Just Another Virtual Accelerator.
Q3. Why is Java called JVM?
It functions as a virtual machine, translating Java bytecode into machine language.
Q4. What concepts should I focus on for Java MCQ interviews?
We should focus on various concepts such as Basic Syntax and Data Types, Operators Control Structures (if-else, switch, loops), Arrays and Strings, Object-Oriented Programming (OOP), Exception Handling, Collections Framework, Java Memory Management, Java I/O and NIO
Q5. How can I effectively prepare for Java MCQ questions?
To effectively prepare for Java MCQ questions:
- Review Core Concepts: Focus on key topics such as OOP, collections, exceptions, multithreading, and Java 8+ features.
- Practice Coding: Solve coding problems on platforms like LeetCode or HackerRank to reinforce your understanding.
- Use Online Resources: Take advantage of Java quizzes and MCQ practice tests available online.
- Study Past Papers: Go through previous interview questions to identify common patterns.
- Read Documentation: Familiarize yourself with Java documentation for detailed explanations and examples.
- Join Study Groups: Engage with peers to discuss concepts and solve problems together.
- Utilize Flashcards: Create flashcards for quick revision of important concepts and syntax.
By combining these strategies, you'll build a strong foundation and improve your confidence in tackling Java MCQs.
Q6. What are some common mistakes to avoid in Java MCQ interviews?
Overlooking Details, Confusing Similar Concepts, Neglecting Syntax, Skipping Basics, Not Practicing Enough, Ignoring Time Management , Relying on Memory
Q7. What additional Java skills can make me stand out in an interview?
To stand out in a Java interview, consider developing additional skills such as ,Advanced Java Features Spring Framework, Hibernate, Microservices, Design Patterns, Testing, integration testing, test-driven development (TDD), DevOps Tools, and also soft skills
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