hierarchyrelationshiptest3.java

《Java面向对象程序设计》例子源代码.轻松学习书本.

// HierarchyRelationshipTest3.java
public class HierarchyRelationshipTest3 { 
   public static void main( String[] args ) {
      Point3 point; 
      Circle3 circle = new Circle3( 120, 89, 2.7 );       
      point = circle;    					//将子类对象的引用赋给超类变量
      int x = point.getX();
      int y = point.getY();
      point.setX( 10 );  
      point.setY( 20 );
      point.toString();
      double radius = point.getRadius();				//超类变量调用子类方法
      point.setRadius( 33.33 );						//超类对象调用子类方法
      double diameter = point.getDiameter();			//超类对象调用子类方法
      double circumference = point.getCircumference();	//超类对象调用子类方法
      double area = point.getArea();					//超类对象调用子类方法
   } 
}