初步认识Java中的向上转换

package object;

 class Animal {
         public void eat(){
                   System.out.println("animal eatting...");
         }
}

class Bird extends Animal{
         public void eat(){
                   System.out.println("bird eatting...");
         }

         public void fly(){
                   System.out.println("bird flying...");
         }
}

public class E05_DataOnly2{      

         public static void main(String[] args) {

                   Animal b=new Bird(); //向上转型
                   b.eat();
                // b.fly();  //此处提示在Animal中没有定义fly方法。
         }
}/* Output:
  bird eatting...
*///:~