[20-05-04][Thinking in Java 7]Java Polymorphism 1 - Upcasting

1 package test_1_5;
2 
3 public class Cycle {
4 
5     public void ride(Cycle c) {
6         
7         System.out.println("ride");
8     }
9 }

1 package test_1_5;
2 
3 public class Unicycle extends Cycle{
4 
5 }

1 package test_1_5;
2 
3 public class Bicycle extends Cycle{
4 
5 }

1 package test_1_5;
2 
3 public class Tricycle extends Cycle{
4 
5 }

 1 package test_1_5;
 2 
 3 public class Test {
 4     
 5     public static void riding(Cycle c) {
 6         
 7         c.ride(c);
 8     }
 9 
10     public static void main(String[] args) {
11 
12         Unicycle unicycle = new Unicycle();
13         Bicycle bicycle = new Bicycle();
14         Tricycle tricycle = new Tricycle();
15         
16         unicycle.ride(unicycle);
17         bicycle.ride(bicycle);
18         tricycle.ride(tricycle);
19         
20         riding(unicycle);
21         riding(bicycle);
22         riding(tricycle);
23     }
24 
25 }