Java Classes & Objects

Predict the output of following Java program?

class Test {

int i;

}

class Main {

public static void main(String args[]) {

Test t;

System.out.println(t.i);

}

• 0

• garbage value

• Compiler Error

• Run Time Error

Predict the output of following Java program

class Test

{ int i;

}

class Main

{ public static void main(String args[])

{ Test t = new Test();

System.out.println(t.i);

} }

• Garbage Value

• 0

• Compiler Error

• Runtime error

class demo

{

int a, b;

demo()

{

a = 10;

b = 20;

}

public void print()

{

System.out.println ("a = " + a + " b = " + b );

}

}

class Test

{

public static void main(String[] args)

{

demo obj1 = new demo();

obj1.a += 1;

obj1.b += 1;

System.out.println ("values of obj1 : ");

obj1.print();

}

}

• Compile error

• values of obj1:

  a = 11 b = 21

• values of obj1:

  a = 10 b = 20

• Runtime Error

What will be the output of the following program?

public class Rose {

public Rose(String name) {

System.out.println("Passed Name is :" + name);

}

public static void main(String[] args) {

Rose myRose = new Rose("red");

myRose = new Rose("white");

}

}

• Passed Name is :red

• Passed Name is :white

• Passed Name is :red

  Passed Name is :white

• Compilation Error or Runtime Error

Given that Student is a class, how many reference variables and objects are created by the following

Student studentName, studentId; studentName = new Student(); Student stud_class = new Student();

• Three reference variables and two objects are created.

• Two reference variables and two objects are created.

• One reference variable and two objects are created

• Three reference variables and three objects are created.