II B.Tech II Sem CSE Java Lab Exercise – 8 (Runtime Polymorphism)
a)Runtime Polymorphism
Aim: To write a JAVA program that implements Runtime polymorphism
Description:
Program:
class A
{
void display()
{
System.out.println("Inside A class");
}
}
class B extends A
{
void display()
{
System.out.println("Inside B class");
}
}
class C extends A
{
void display()
{
System.out.println("Inside C class");
}
}
class runtimedemo
{
public static void main(String args[])
{
A a1=new A();
B b1=new B();
C c1=new C();
A ref;
ref=c1;
ref.display();
ref=b1;
ref.display();
ref=a1;
ref.display();
}
}
Output:
II B.Tech II Sem CSE Java Lab Exercise - 7b (Exception)
b) Illustrating multiple catch classes
Aim:To write a JAVA program Illustrating Multiple catch clauses
Description:
Program:
class multitrydemo
{
public static void main(String args[])
{
try
{
int a=10,b=5;
int c=a/b;
int d[]={0,1};
System.out.println(d[10]);
System.out.println(c);
}
catch(ArithmeticException e)
{
System.out.println(e);
}
catch(ArrayIndexOutOfBoundsException e)
{
System.out.println(e);
}
System.out.println("After the catch statement");
}
}
Output:
II B.Tech II Sem CSE Java Lab Exercise - 7a (Exception)
a) Exception handling mechanism
Aim: To write a JAVA program that describes exception handling mechanism
Description:
Program:
Usage of Exception Handling:
class trydemo
{
public static void main(String args[])
{
try
{
int a=10,b=0;
int c=a/b;
System.out.println(c);
}
catch(ArithmeticException e)
{
System.out.println(e);
}
System.out.println("After the catch statement");
}
}
Output:
II B.Tech II Sem CSE Java Exercise - 6 b(Inheritance - Continued)
b) Implementing interface
Aim:To write a JAVA program to implement Interface.
Description:
Program:
(i) First form of interface implementation
interface A
{
void display();
}
class B implements A
{
public void display()
{
System.out.println("B's method");
}
}
class C extends B
{
public void callme()
{
System.out.println("C's method");
}
}
class interfacedemo
{
public static void main(String args[])
{
C c1=new C();
c1.display();
c1.callme();
}
}
Output:
(ii) Second form of interface implementation
interface D
{
void display();
}
interface E extends D
{
void show();
}
class A
{
void callme()
{
System.out.println("This is in callme method");
}
}
class B extends A implements E
{
public void display()
{
System.out.println("This is in display method");
}
public void show()
{
System.out.println("This is in show method");
}
}
class C extends B
{
void call()
{
System.out.println("This is in call method");
}
}
class interfacedemo1
{
public static void main(String args[])
{
C c1=new C();
c1.display();
c1.show();
c1.callme();
c1.call();
}
}
Output:
(iii) Third form of interface implementation
interface A
{
void display();
}
class B implements A
{
public void display()
{
System.out.println("This is in B's method");
}
}
class C implements A
{
public void display()
{
System.out.println("This is C's method");
}
}
class interfacedemo2
{
public static void main(String args[])
{
B b1=new B();
C c1=new C();
b1.display();
c1.display();
}
}
Output:
(iv) Fourth form of interface implementation
interface A
{
void display();
}
interface B
{
void callme();
}
interface C extends A,B
{
void call();
}
class D implements C
{
public void display()
{
System.out.println("interface A");
}
public void callme()
{
System.out.println("interface B");
}
public void call()
{
System.out.println("interface C");
}
}
class interfacedemo3
{
public static void main(String args[])
{
D d1=new D();
d1.display();
d1.callme();
d1.call();
}
}
Output:
II B.Tech II Sem CSE Java Exercise - 6 a(Inheritance - Continued)
a)super keyword implementation
Aim: Write a JAVA program give example for “super” keyword
Description:
Program:
(i)Using super to call super class constructor (Without parameters)
class A
{
int l,b;
A()
{
l=10;
b=20;
}
}
class B extends A
{
int h;
B()
{
super();
h=30;
}
int volume()
{
return l*b*h;
}
}
class superdemo
{
public static void main(String args[])
{
B b1=new B();
int r=b1.volume();
System.out.println("The vol. is: "+r);
}
}
Output:
(ii)Using super to call super class constructor (With parameters)
class A
{
int l,b;
A(int u,int v)
{
l=u;
b=v;
}
}
class B extends A
{
int h;
B(int u,int v,int w)
{
super(u,v);
h=w;
}
int volume()
{
return l*b*h;
}
}
class superdemo1
{
public static void main(String args[])
{
B b1=new B(30,20,30);
int r=b1.volume();
System.out.println("The vol. is: "+r);
}
}
Output:
II B.Tech II Sem CSE Java Lab Exercise - 5c (Inheritance)
c)Abstract Class
Aim: To write a java program for abstract class to find areas of different shapes
Description:
Program:
abstract class shape
{
abstract double area();
}
class rectangle extends shape
{
double l=12.5,b=2.5;
double area()
{
return l*b;
}
}
class triangle extends shape
{
double b=4.2,h=6.5;
double area()
{
return 0.5*b*h;
}
}
class square extends shape
{
double s=6.5; double area()
{
return 4*s;
}
}
class shapedemo
{
public static void main(String[] args)
{
rectangle r1=new rectangle();
triangle t1=new triangle();
square s1=new square();
System.out.println("The area of rectangle is: "+r1.area());
System.out.println("The area of triangle is: "+t1.area());
System.out.println("The area of square is: "+s1.area());
}
}
Output:
II B.Tech II Sem CSE Java Lab Exercise - 5b (Inheritance)
b)Multi level Inheritance
Aim: To write a JAVA program to implement multi level Inheritance
Description:
Program:
class Car
{
public Car()
{
System.out.println("Class Car");
}
public void vehicleType()
{
System.out.println("Vehicle Type: Car");
}
}
class Maruti extends Car
{
public Maruti()
{
System.out.println("Class Maruti");
}
public void brand()
{
System.out.println("Brand: Maruti");
}
public void speed()
{
System.out.println("Max: 90Kmph");
}
}
public class Maruti800 extends Maruti
{
public Maruti800()
{
System.out.println("Maruti Model: 800");
}
public void speed()
{
System.out.println("Max: 80Kmph");
}
public static void main(String args[])
{
Maruti800 obj=new Maruti800();
obj.vehicleType();
obj.brand();
obj.speed();
}
}
Output:
II B.Tech II Sem CSE Java Lab Exercise - 5a (Inheritance)
a)Implementing Single Inheritance
Aim: To write a JAVA program to implement Single Inheritance
Description:
Program:
class Shape
{
int length;
int breadth;
}
class Rectangle extends Shape
{
int area;
public void calcualteArea()
{
area = length*breadth;
}
public static void main(String args[])
{
Rectangle r = new Rectangle();
r.length = 10;
r.breadth = 20;
r.calcualteArea();
System.out.println("The Area of rectangle of length \""
+r.length+"\" and breadth \""+r.breadth+"\" is \""+r.area+"\"");
}
}
Output:
