java 15-10-2023

public class Test

{

    public Test()

    {

        System.out.printf("1");

        new Test(10);

        System.out.printf("5");

    }

    public Test(int temp)

    {

        System.out.printf("2");

        new Test(10, 20);

        System.out.printf("4");

    }

    public Test(int data, int temp)

    {

        System.out.printf("3");

         

    }

     

    public static void main(String[] args)

    {

        Test obj = new Test();

         

    }

     

}

• 12345

• Compilation error

• 15

• Runtime error 

public class Outer

{

    private int data = 10;

      

    class Inner

    {

        private int data = 20;

        private int getData()

        {

            return data;

        }

        public void main(String[] args)

        {

            Inner inner = new Inner();

            System.out.println(inner.getData());

              

        }

    }

    private int getData()

    {

        return data;

    }

    public static void main(String[] args)

    {

        Outer outer = new Outer();

        Outer.Inner inner = outer.new Inner();

        System.out.printf("%d", outer.getData());

        inner.main(args);

    }

}

• 2010

• 1020

• Compilation Error

• None of these

class Derived 

{

    public void getDetails()

    {

        System.out.printf("Derived class ");

    }

}

  

public class Test extends Derived

{

    public void getDetails()

    {

        System.out.printf("Test class ");

        super.getDetails();

    }

    public static void main(String[] args)

    {

        Derived obj = new Test();

        obj.getDetails();

    }

}

• Test class Derived class

• Derived class Test class

• Compilation error

• Runtime error

Predict the Output of the following code.
class Clidder 

{

    private final void flipper() 

    {

        System.out.println("Clidder");

    }

}

  

public class Clidlet extends Clidder 

{

    public final void flipper() 

    {

        System.out.println("Clidlet");

    }

    public static void main(String[] args) 

    {

        new Clidlet().flipper();

    }

}

class Grandparent 

{

    public void Print() 

    {

        System.out.println("Grandparent's Print()"); 

    } 

}

  

class Parent extends Grandparent 

{

    public void Print() 

    {

        System.out.println("Parent's Print()"); 

    } 

}

  

class Child extends Parent 

{

    public void Print()   

    {

        super.super.Print();

        System.out.println("Child's Print()"); 

    } 

}

  

public class Main 

{

    public static void main(String[] args) 

    {

        Child c = new Child();

        c.Print(); 

    }

}

• Child's Print()

• Parent's Print()

• Grandparent's Print()

• Compiler Error

Answer explanation

Error in in super.super.Print()
It is not allowed to do super.super. We can only access Grandparent’s members using Parent

public class Test

{

    private String function()

    {

        return ("GFG");

    }

    public final static String function(int data)

    {

        return ("GeeksforGeeks");

    }

    public static void main(String[] args)

    {

        Test obj = new Test();

        System.out.println(obj.function());   

    }

}

• Compilation error 

• Runtime error 

• GFG 

• None of these

class Main {

 public static void main(String args[]){

    final int i;

    i = 20;

    i = 30;

    System.out.println(i);

 }

}

• 20

• Compiler Error

• Garbage value

• 30

Answer explanation

i is assigned a value twice. Final variables can be assigned values only one. Following is the compiler error “Main.java:5: error: variable i might already have been assigned”

public class A extends B

{

    public static String sing()

    {

        return "fa";

    }

    public static void main(String[] args)

    {

        A a = new A();

        B b = new A();

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

    }

}

class B

{

    public static String sing()

    {

        return "la";

    }

}

class Test {

   public static void main(String args[]) {

     int arr[2];  

     System.out.println(arr[0]);

     System.out.println(arr[1]);

   }

}

• 0

  0

• garbage value

  garbage value

• Compiler Error

• Exception

Answer explanation

it is not allowed to put the size of the array in the declaration because an array declaration specifies only the element type and the variable name. The size is specified when you allocate space for the array.

abstract class demo

{

    public int a;

    demo()

    {

        a = 10;

    }

 

    abstract public void set();

     

    abstract final public void get();

 

}

 

class Test extends demo

{

 

    public void set(int a)

    {

        this.a = a;

    }

 

    final public void get()

    {

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

    }

 

    public static void main(String[] args)

    {

        Test obj = new Test();

        obj.set(20);

        obj.get();

    }

}

• a = 10

• a = 20

• Compilation error

Answer explanation

Final method can’t be overridden. Thus, an abstract function can’t be final.