In Java, each child class can have only one parent.

What is the output of the following program?

1. class  Parent{  
2.    void PrintData() {  
3.       System.out.println("method of parent class");  
4.    }  
5. }  
6.   
7. class Child extends Parent {  
8.    void PrintData() {  
9.       System.out.println("method of child class");  
10.    }  
11. }  
12. class UpcastingExample{  
13.    public static void main(String args[]) {  
14.         
15.       Parent obj1 = (Parent) new Child();  
16.       Parent obj2 = (Parent) new Child();   
17.       obj1.PrintData();  
18.       obj2.PrintData();  
19.    }  
20. }  

What is the purpose of upcasting in Java? 

What is the output of the following code snippet?

class Person{
	String name;
	Person(){
       System.out.println("In Person class");
    }
}
class Student extends Person{
	Student(){
       System.out.println("In Student class");
    }
	int id;
	public static void main(String[] a){
		Student ob=new Student(); //Line 1
		ob.name="abc"; //Line 2
		ob.id=123;}
}

What is the output of this program

class Person{

class Employee extends Person{

class Customer extends Person{

this.salary=salary;

class Account {

What is the output of the following program?

class SolarSystem {

System.out.println(s instanceof SolarSystem);

What is the output of the following program?

1. class Parent {   
2.     String name;   
3.     
4.     void showMessage()   

5.     {   
6.         System.out.println("Parent method is called");   
7.     }   
8. }   
9. class Child extends Parent {   

10.     int age;   
11.     
12.     @Override  

13.     void showMessage()   
14.     {   
15.         System.out.println("Child method is called");   
16.     }   
17. }   
18.     
19. public class Downcasting{  
20.     
21.     public static void main(String[] args)   
22.     {   
23.         Parent p = new Child();  
24.         p.name = "Adrian";  
25.       
26.         Child c = (Child)p;   
27.         c.age = 18;   
28.         System.out.println(c.name);   
29.         System.out.println(c.age);   
30.         c.showMessage();   
31.     }   
32. }  

What is the output of the following program?

class Animal {

protected void display() {

class Dog extends Animal {

class Main {

// create an object of the subclass

// access protected field and method

labrador.getInfo();

In order to restrict a variable of a class from inheriting to subclass, how variable should be declared?

What is the output of this program?

class A {

    int i;}

class B extends A {

        int j;

    void display() 

    {   super.i = j + 1;

        System.out.println(j + " " + i); }

}    

class inheritance {

    public static void main(String args[]) {

        B obj = new B();

       obj.i=1;

       obj.j=2;   

       obj.display(); }

}