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web.groovymark@gmail.com
- December 26, 2024
Question 41
What will be the output of System.out.println(3 + 4 + “Java”);?
- A. 7Java
- B. Java34
- C. 34Java
- D. 3 + 4 + Java
Answer: A
Explanation: The expression evaluates to "7Java" due to string concatenation.
Question 42
What is the purpose of the finally block in Java?
- A. It always executes after try-catch
- B. It is used for resource cleanup
- C. It handles exceptions
- D. Both A and B
Answer: D
Explanation: The finally block always executes after the try-catch blocks and is typically used for resource cleanup.
Question 43
How do you compare two objects for reference equality?
- A. ==
- B. equals()
- C. compareTo()
- D. isEqual()
Answer: A
Explanation: The == operator checks for reference equality, determining if two object references point to the same object.
Question 44
Which keyword is used to define a constant variable in Java?
- A. const
- B. final
- C. static
- D. constant
Answer: B
Explanation: The final keyword is used to define a constant variable that cannot be modified.
Question 45
What is the default value of an uninitialized int variable in Java?
- A. 0
- B. null
- C. -1
- D. Undefined
Answer: A
Explanation: The default value of an uninitialized int variable in Java is 0.
Question 46
How do you handle an unchecked exception in Java?
- A. You must catch it with a try-catch block
- B. You can ignore it
- C. It must be declared in the method signature
- D. It cannot be handled
Answer: B
Explanation: Unchecked exceptions (like RuntimeExceptions) do not need to be caught or declared.
Question 47
Which of the following methods can be used to iterate over elements in a List?
- A. Using a for loop
- B. Using an enhanced for loop
- C. Using an iterator
- D. All of the above
Answer: D
Explanation: You can iterate over elements in a List using a standard for loop, an enhanced for loop, or an iterator.
Question 48
What is the purpose of the static keyword?
- A. To declare a class variable that can be accessed without an object
- B. To prevent method overriding
- C. To create an instance variable
- D. To define an abstract class
Answer: A
Explanation: The static keyword declares a class variable that can be accessed without creating an object of the class.
Question 49
How do you convert a string to a character array in Java?
- A. str.toCharArray()
- B. str.getChars()
- C. str.charAt()
- D. str.toChar()
Answer: A
Explanation: The toCharArray() method converts a string to a character array.
Question 50
What is the purpose of the volatile keyword in Java?
- A. To indicate that a variable may be changed unexpectedly
- B. To prevent method overriding
- C. To define a constant
- D. To create a synchronized block
Answer: A
Explanation: The volatile keyword indicates that a variable's value may be changed by different threads unexpectedly, ensuring visibility of its changes.
