Programming in Java - Output Prediction

Predict the output:

class Test {

protected int x=10, y=10;

}

class Main {

public static void main(String args[]) {

Test t = new Test();

System.out.println(t.x + " " + t.y);

}

}

• Garbage Value

• 0 0

• 10 10

• 5 5

Predict the output:

class Test {

private static int x;

public static void main(String args[]) {

System.out.println(fun());

}

static int fun() {

return ++x;

}

}

• 1

• Error

• 0

• Garbage Value

Predict the output:

class Base {

public void Print()

{

System.out.println("Base");

}

}

class Derived extends Base {

public void Print()

{

System.out.println("Derived");

}

}

class Main {

public static void DoPrint(Base o)

{

o.Print();

}

public static void main(String[] args)

{

Base x = new Base();

Base y = new Derived();

Derived z = new Derived();

DoPrint(x);

DoPrint(y);

DoPrint(z);

}

}

• Base

  Derived

  Base

• Base

  Derived

  Derived

• Derived

  Base

  Derived

• Derived

  Derived

  Base

Predict the output:

class Test {

int x = 10;

public static void main(String[] args)

{

Test t = new Test();

System.out.println(t.x);

}

}

• 1

• 0

• 10

• 11

Predict the output:

class Base {

protected void foo() {}

}

class Derived extends Base {

void foo() {}

}

public class Main {

public static void main(String args[]) {

Derived d = new Derived();

d.foo();

}

}

• Runtime Error

• Garbage Value

• 0

• Compile time Error