Questions and answers for exam Preparation

MCQs

Total Questions : 10

What is the output of this program?

class recursion {
int fact(int n) {
int result;
if (n == 1)
return 1;
result = fact(n - 1) * n;
return result;
}
}
class Output {
public static void main(String args[]) {
recursion obj = new recursion() ;
System.out.print(obj.fact(6));
}
}

Discuss Question

Answer: Option D. -> 720

None.
Output:
$ javac Output.javac
$ java Output
720

Question 2.

What is the output of this program?

1
30
120
Runtime Error

Discuss Question

Answer: Option A. -> 1

fact() method recursively calculates factorial of a number, when value of n reaches 1,

base case is excuted and 1 is returned.
Output:
$ javac Output.javac
$ java Output
1

Question 3.

What is the output of this program?

Discuss Question

Answer: Option C. -> 120

fact() method recursively calculates factorial of a number, when value of n reaches 1,

base case is excuted and 1 is returned.
Output:
$ javac Output.javac
$ java Output
120

Question 4.

What is the output of this program?

class recursion {
int func (int n) {
int result;
if (n == 1)
return 1;
result = func (n - 1);
return result;
}
}
class Output {
public static void main(String args[]) {
recursion obj = new recursion() ;
System.out.print(obj.func(5));
}
}

0
1
120
None of the mentioned

Discuss Question

Answer: Option B. -> 1

None.
Output:
$ javac Output.javac
$ java Output
1

Question 5.

What is the output of this program?

class recursion {
int func (int n) {
int result;
result = func (n - 1);
return result;
}
}
class Output {
public static void main(String args[]) {
recursion obj = new recursion() ;
System.out.print(obj.func(12));
}
}

0
1
Compilation Error
Runtime Error

Discuss Question

Answer: Option D. -> Runtime Error

Since the base case of the recursive function func() is not defined hence infinite loop

occurs and results in stackoverflow.
Output:
$ javac Output.javac
$ java Output
Exception in thread "main" java.lang.StackOverflowError

Question 6.

Which of these packages contains the exception Stackoverflow in Java?

java.lang
java.util
java.io
java.system

Discuss Question

Answer: Option A. -> java.lang

None.

Question 7.

Which of these will happen if recursive method does not have a base case?

An infinite loop occurs
System stops the program after some time.
After 1000000 calls it will be automatically stopped.
None of the mentioned

Discuss Question

Answer: Option A. -> An infinite loop occurs

If a recursive method does not have a base case then an infinite loop occurs which

results in stackoverflow.

Question 8.

Which of these data types is used by operating system to manage the Recursion

in Java?

Array
Stack
Queue
Tree

Discuss Question

Answer: Option B. -> Stack

Recursions are always managed by using stack.

Question 9.

What is Recursion in Java?

Recursion is a class.
Recursion is a process of defining a method that calls other methods repeatedly.
Recursion is a process of defining a method that calls itself repeatedly.
Recursion is a process of defining a method that calls other methods which in turn call again this method.

Discuss Question

Answer: Option B. -> Recursion is a process of defining a method that calls other methods repeatedly.

Recursion is the process of defining something in terms of itself. It allows us to

Question 10.

Which of these is not a correct statement?

A recursive method must have a base case.
Recursion always uses stack.
Recursive methods are faster that programmers written loop to call the function repeatedly using a stack.
Recursion is managed by Java's Run - Time environment.

Discuss Question

Answer: Option D. -> Recursion is managed by Java's Run - Time environment.

Recursion is always managed by operating system.