Online Random Test

Ques 1 :
Which of these statements is true?

(A) AbstractSet extends Set

(B) LinkedList extends List

(D) WeakHashMap extends HashMap

Ques 2 :
What happens when the following program is compiled and executed with the command - java test. Select the one correct answer.
class test
{
public static void main(String args[])
{
if(args.length > 0)
System.out.println(args.length);
}
}

(A) The program compiles and runs but does not print anything.

(B) The program compiles and runs and prints 0

(D) The program compiles and runs and prints 2

Ques 3 : Is this True or False. In Java a final class must be sub-classed before it can be used.

(A) True

(B) False

Ques 4 : Is this True or False. In Java an abstract class cannot be sub-classed.

(A) True

(B) False

Ques 5 :
Which of these are core interfaces in the collection framework. Select the one correct answer.

(A) Tree

(B) Array

(D) Map

Ques 6 :
Assume that class A extends class B, which extends class C. Also all the three classes implement the method test(). How can a method in a class A invoke the test() method defined in class C (without creating a new instance of class C). Select the one correct answer.

(A) test();

(B) super.test();

(D) It is not possible to invoke test() method defined in C from a method in A.

Ques 7 : Name the access modifier which when used with a method, makes it available to all the classes in the same package and to all the subclasses of the class.

(A) public

(B) private

(D) default

Ques 8 :
Select the one correct answer. Which method defined in Integer class can be used to convert an Integer object to primitive int type.

(A) valueOf

(B) intValue

(D) getInteger

Ques 9 :
What all gets printed when the following program is compiled and run. Select the two correct answers.

public class test {
public static void main(String args[]) {
int i, j=1;
i = (j>1)?2:1;
switch(i) {
case 0: System.out.println(0); break;
case 1: System.out.println(1);
case 2: System.out.println(2); break;
case 3: System.out.println(3); break;
}
}
}
a. 0
b. 1
c. 2
d. 3

(A) a, b

(B) b, c

(D) c, d

Ques 10 :
Which of the following is a Java keyword. Select the four correct answers.
a. extern
b. synchronized
c. volatile
d. friend
e. friendly
f. transient
g. this
h. then

(A) b, c

(B) b, c, f, g

(D) all of above.

Ques 11 :
What happens when the following program is compiled and run. Select the one correct answer.
public class example
{
int i[] = {0};
public static void main(String args[])
{
int i[] = {1};
change_i(i);
System.out.println(i[0]);
}
public static void change_i(int i[])
{
i[0] = 2;
i[0] *= 2;
}
}

(A) The program prints 0

(B) The program prints 1.

(D) The program prints 4.

Ques 12 :
What kind of thread is the Garbage collector thread is?

(A) Non daemon thread

(B) Daemon thread

(D) None of the above

Ques 13 :
Which of these statements are legal. Select the three correct answers.
a. int arr[][] = new int[5][5];
b. int []arr[] = new int[5][5];
c. int[][] arr = new int[5][5];
d. int[] arr = new int[5][];
e. int[] arr = new int[][5];

(A) a, b

(B) a, b, c

(D) a, b, c, d, e

Ques 14 :
What gets printed on the standard output when the class below is compiled and executed. Select the one correct answer.

public class ShortCkt {
public static void main(String args[]) {
int i = 0;
boolean t = true;
boolean f = false, b;
b = (t | ((i++) == 0));
b = (f | ((i+=2) > 0));
System.out.println(i);
}
}

(A) 0

(B) 1

(D) 3

Ques 15 :
In implementing two classes Employee and Manager, such that each Manager is an Employee, what should be the relationship between these classes. Select the one correct answer.

(A) Employee should be the base class of Manager class.

(B) Manager should be the base class of Employee class.

(D) Employee class should include Manager class as a data member.

Ques 16 : What is an aggregate object?

(A) An object with only primitive attributes

(B) An instance of a class which has only static methods