1. What does the compareTo() method return when two objects are equal?

2. What is the primary difference between delete and delete[]?

3. What is the use of std::priority_queue?

4. A ridesharing application uses a Singleton class to manage its global configuration settings. What is a downside of this approach?

5. Which function is used to allocate memory in C?

6. Which header file is required to use the strlen function?

7. What does the malloc function return if memory allocation fails?

8. What is the output of this code?

#include

int main() {

int a[5] = {1, 2, 3, 4, 5};

printf("%d", *(a + 3));

return 0;

}

9. A car rental system has a Vehicle class with subclasses like Car and Bike. If Vehicle cannot be instantiated, which feature is being used?

10. Which of the following best represents "hasa" relationships in Java?

11. In an order management system, a final class Order is used to prevent extension. What is the primary advantage of this?

12. What is the output of this code?

int a = 5, b = 10;

std::swap(a, b);

std::cout << a << " " << b;

13. What is the output of the following code?
java
class Test {
public static void main(String[] args) {
int[][] arr = {{1, 2}, {3, 4}};
System.out.println(arr[1][1]);
}
}

14. An online shopping application has a Cart class that stores Product objects. How should this relationship be modeled?

15. What does the following program output?

#include

void main() {

int a = 0;

while (a++ < 5) {} printf("%d", a); }

16. What happens when a derived class constructor calls a base class constructor?

17. Which of the following algorithms is NOT part of STL?

18. What is the time complexity of std::map::find()?

19. What is the primary purpose of decltype?

20. Which of the following is NOT a valid preprocessor directive?