chapter09.java

适合于初学者使用的许多经典的实例

//-----------------------------------------------------------关于继承的简单的例子-----------------------------------------------------------------//

class C_Circle {
	     private double pi=3.14;
	     private double radius;
	     
	     public C_Circle() {                             // C_Circle() 构造函数 ------------------------------------------------------------------------
	     	     System.out.println("C_Circle() contructor called !");
	     }
	     
	     public void setRadius(double r) {
	     	     radius=r;
	     	     System.out.println("Radius="+radius);
	     }
	     
	     public void show() {
	     	     System.out.println("Area="+pi*radius*radius);
	     }
}


class C_Coin extends C_Circle {          // 定义类 C_Coin 类，继承自类 C_Circle------注意语法格式-------------------
	     private int value;
	     public C_Coin() {                                // C_Coin() 构造函数--------------------------------
	     	     System.out.println("C_Coin() contrustor called !");
	     }
	     
	     public void setValue(int t) {
	     	     value=t;
	     	     System.out.println("Value="+value);
	     }
}


public class Chapter09 {
         public static void main(String[] args) {    
                 C_Coin coin=new C_Coin();
                 coin.setRadius(2.8);
                 coin.show();
                 coin.setValue(10);                 
         }
}