fork download 
  1. abstract class Figure { 
  2. double dim1; 
  3. double dim2; 
  4. Figure(double a, double b) { 
  5. dim1 = a; 
  6. dim2 = b; 
  7. } 
  8. // area is now an abstract method 
  9. abstract double area(); 
  10. }
  11. class Rectangle extends Figure { 
  12. Rectangle(double a, double b) { 
  13. super(a, b); 
  14. } 
  15. // override area for rectangle 
  16. double area() { 
  17. System.out.println("Inside Area for Rectangle."); 
  18. return dim1 * dim2; 
  19. } 
  20. }
  21.  
  22. class Triangle extends Figure { 
  23. Triangle(double a, double b) { 
  24. super(a, b); 
  25. } 
  26. // override area for right triangle 
  27. double area() { 
  28. System.out.println("Inside Area for Triangle."); 
  29. return dim1 * dim2 / 2; 
  30. } 
  31. }
  32.  
  33. class AbstractAreas { 
  34. public static void main(String args[]) { 
  35. // Figure f = new Figure(10, 10); // illegal now 
  36. Rectangle r = new Rectangle(9, 5); 
  37. Triangle t = new Triangle(10, 8); 
  38. Figure figref; // this is OK, no object is created 
  39. figref = r; 
  40. System.out.println("Area is " + figref.area()); 
  41. figref = t; 
  42. System.out.println("Area is " + figref.area()); 
  43. } 
  44. }
Runtime error #stdin #stdout 0.02s 245632KB
comments (?)
stdin 
Standard input is empty
stdout 
Standard output is empty
https://ideone.com/NQPx8
language:
Java (HotSpot 12)
created:
14 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!