Test : Java_6

This test contains 10 questions based on Java.
Each question answered correctly awards you 1 point and each incorrect answer has a penalty of -0.25 points, no points are deducted for unattempted answers.

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You Get +1 for each correct answer and -0.25 for each incorrect answer

Time Left - minutes :seconds

Given the class definitions

System.out.print(b.display() + " ");
System.out.print(d.display() + " ");
System.out.print(bd.display() + " ");
System.out.println();

will display:

Base Derived Derived	Base Base Derived
Base Derived Base	Derived Derived Derived

A

Which of the following keywords are used to control access to a class member? (A) default (B) abstract (C) protected (D) interface (E) public

(C) & (E)	(A), (C) & (E)
(B), (C) & (E)	All of these

C

Which operator is used by Java run time implementations to free the memory of an object when it is no longer needed?

delete	free
new	None of the mentioned

D

Java handles deallocation of memory automatically, we do not need to explicitly delete an element. Garbage collection only occurs during execution of the program. When no references to the object exist, that object is assumed to be no longer needed, and the memory occupied by the object can be reclaimed.

What is the output of this program?

 class string_demo {
        public static void main(String args[])
        {
            String obj = "I" + "like" + "Java";   
            System.out.println(obj);     
        }
   }

l	like
likajava	llikejava

D

Which of these keyword must be used to inherit a class?

super	this
extent	extends

D

An interface can only contain abstract methods. True or False?

True	False

A

What is the output of this program?

class ternary_operator {
        public static void main(String args[]) 
        {        
             int x = 3;
             int y = ~ x;
             int z;
             z = x > y ? x : y;
             System.out.print(z);
        } 
    }

0	1
3	-4

C

Which of the following defines a legal abstract class?

(A)class Vehicle {

              abstract void display(); } 
(B)abstract class Vehicle {

              abstract void display(); }
(C)abstract Vehicle {

              abstract void display(); } 
(D)class abstract Vehicle {

              abstract void display(); } 
              System.out.println("Car"); }} 

class Vehicle {                    abstract void display(); }    class Vehicle {<br> abstract void display(); }	abstract class Vehicle {                    abstract void display(); }   abstract class Vehicle {<br> abstract void display(); }
abstract Vehicle {                    abstract void display(); }    abstract Vehicle {<br> abstract void display(); }	class abstract Vehicle {                    abstract void display(); }    class abstract Vehicle {<br> abstract void display(); }

B

What is the output of this program?

class newthread implements Runnable {
 Thread t;
        newthread() {
            t = new Thread(this,"My Thread");
            t.start();
 }
 public void run() {
     System.out.println(t.getName());
 }
    }
    class multithreaded_programing {
        public static void main(String args[]) {
            new newthread();        
        }
    }

My Thread	Thread[My Thread,5,main]
Compilation Error	Runtime Error

A

Which of these methods can convert an object into a List?

SetList()	ConvertList()
singletonList()	CopyList()

C

singletonList() returns the object as an immutable List. This is a easy way to convert a single object into a list. This was added by Java 2.0.

Finish Test