//Program to design a vehicle class hierarchy in Java, and develop a program to demonstrate Polymorphism. class Vehicle { String regno; int model; Vehicle(String r, int m) { regno = r; model = m; } void display() { System.out.print("\nRegistration no: "+regno); System.out.print("\nModel no: "+model); } } class Twowheeler extends Vehicle { int noofwheels; Twowheeler(String r, int m, int n) { super(r,m); noofwheels = n; } void display() { System.out.print("\nTwo wheeler tvs"); super.display(); System.out.print("\nNo. of wheels: " + noofwheels); } } class Threewheeler extends Vehicle { int noofwheels; Threewheeler(String r,int m,int n) { super(r,m); noofwheels = n; } void display() { System.out.print("\nThree wheeler auto"); super.display(); System.out.print("\nNo. of wheels: " +noofwheels); } } class Fourwheeler extends Vehicle { int noofwheels; Fourwheeler(String r,int m,int n) { super(r,m); noofwheels=n; } void display() { System.out.print("\nFour wheeler car"); super.display(); System.out.print("\nNo. of wheels: " + noofwheels); } } class PolymorphismProgram { public static void main(String arg[]) { Twowheeler t1 = new Twowheeler("KA74 12345", 1,2); Threewheeler th1 = new Threewheeler("KA74 54321", 4,3); Fourwheeler f1 = new Fourwheeler("KA34 45677",5,4); t1.display(); th1.display(); f1.display(); } }