shapetest.java

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import java.util.*;
class Shape{
  void draw(){
    System.out.println(this+".draw()");
  }
}
class Circle extends Shape{
  public String toString(){return "Circle";}
}
class Square extends Shape{
  public String toString(){return "Square";}
}
class Triangle extends Shape{
  public String toString(){return "Triangle";}
}
public class ShapeTest{
  public static void main(String args[]){
    ArrayList s = new ArrayList();
    s.add(new Circle());
    s.add(new Square());
    s.add(new Triangle());
    //s.add(new Shape());
    Iterator e = s.iterator();
    while(e.hasNext())
      ((Shape)e.next()).draw();
  }
}