Question 1. Method A invokes method A itself. This is called _________.

indirect recursion

explicit recursion

direct recursion

one-step recursion

Question 2. What are the base cases in the following recursive method?

public static void recurse(int n)

{

if (n > 0)

{

System.out.print(n % 10);

recurse(n / 10);

}

}

Question 2 options:

n < 0

n <= 0

n > 0

no base cases

Question 3. What will be displayed by the method call recurse(1234)?

public static void recurse(int n)

{

if (n <= 0)

{

System.out.print(n % 10);

recurse(n / 10);

}

}

Question 3 options:

1234

4 3 2 1

Nothing

4321

Question 4. Analyze the following recursive method and indicate which of the following will be true.

public static long factorial(int n)

{

return n * factorial(n - 1);

}

Question 4 options:

Invoking factorial(2) returns 2.

Invoking factorial(1) returns 1.

The method runs infinitely and causes a StackOverflowError.

Invoking factorial(0) returns 0.

Question 5. Fill in the code to complete the following method for computing factorial.

// Return the factorial for a specified index

public static long factorial(int n)

{

if (n == 0)

return 1;

else

return _____________;

}

Question 5 options:

n * (n - 1)

n

n * factorial(n - 1)

factorial(n - 1) * (n - 1)

Question 6. What will be displayed by the method call recurse(6)?

public static int recurse(int n)

{

if (n <= 1)

return 1;

else

return n + recurse(n - 2);

}

Question 6 options:

13

14

11

12

Question 7. The base case _________ the recursion.

Question 7 options:

stops

breaks

pauses

starts

Question 8. What is the output of the following program?

{

public static void main(String[] args)

{

System.out.println(countDown(2, 0));

}

public static int countDown(int n, int result)

{

if (n == 0)

return 0;

else

return countDown(n - 1, n + result);

}

}

Question 8 options:

1

3

0

2

Question 9. Which of the following statements about recursive methods is accurate?

Question 9 options:

They must have exactly 1 base case and exactly 1 recursive case

They must have at least 1 base case and at least 1 recursive case

They must have exactly 1 base case and at least 1 recursive case

They must have at least 1 base case and exactly 1 recursive case

Question 10. Which of the following is a possible disadvantage of recursion?

Recursive solutions can be less efficient than their iterative counterparts

Recursive solutions tend to have more local variables than their iterative counterparts

Recursive solutions tend to be longer than their iterative counterparts

Recursive solutions are more likely to go into infinite loops than their iterative counterparts

Question 11. To declare an interface named A with two generic types, use

public interface A(E) { ... }

public interface A { ... }

public interface A { ... }

public interface A(E, F) { ... }

Question 12. Will the following code have a runtime error?

Comparable date = new Date();

int i = date.compareTo("time");

Question 12 options:

Always

Never

Only when date contains an invalid date

Only when date is not the current date

Question 13. To create a list to store integers, use

Question 13 options:

ArrayList