看了尚学堂视频除了问题
package   com.ch3;

public   class   Animal   {
public   String   name;
public   Animal(String   name){
name=this.name;
}
}
package   com.ch3;

public   class   Cat   extends   Animal   {
public   String   eyeColor;
public   Cat(String   name,String   eyeColor){
super(name);
eyeColor=this.eyeColor;
}
}
package   com.ch3;

public   class   Dog   extends   Animal   {
public   String   furColor;

public   Dog(String   name,   String   furColor)   {
super(name);
furColor   =   this.furColor;
}

}
package   com.ch3;

public   class   TestAnimal   {


public   static   void   main(String[]   args){
TestAnimal   test   =new   TestAnimal();

Cat   cat=new   Cat( "catname ", "redEye ");
test.f(cat);
}
public     void   f(Animal   a){
System.out.println( "Name: "+a.name);
if(a   instanceof   Cat){
Cat   cat=(Cat)a;
System.out.println( "EyeColor: "+cat.eyeColor);
}else   if(a   instanceof   Dog){
Dog   dog=(Dog)a;
System.out.println( "FurColor: "+dog.furColor);
}
}
}
这是我在尚学堂看到老师的一个视频，然后模拟写了一个类似的，但是结果不是我想到的那种，结果是：
Name:null
EyeColor:null
我对了几遍，都看不出来，好郁闷啊！

------解决方案--------------------
package com.ch3;

public class Animal {
public String name;
public Animal(String name){
name=this.name;
}
}
package com.ch3;

public class Cat extends Animal {
public String eyeColor;
public Cat(String name,String eyeColor){
super(name);
this.eyeColor = eyeColor;
}
}
package com.ch3;

public class Dog extends Animal {
public String furColor;

public Dog(String name, String furColor) {
super(name);
this.furColor = furColor;
}

}
package com.ch3;

public class TestAnimal {


public static void main(String[] args){
TestAnimal test =new TestAnimal();

Cat cat=new Cat( "catname ", "redEye ");
test.f(cat);
}
public void f(Animal a){
System.out.println( "Name: "+a.name);
if(a instanceof Cat){
Cat cat=(Cat)a;
System.out.println( "EyeColor: "+cat.eyeColor);
}else if(a instanceof Dog){
Dog dog=(Dog)a;
System.out.println( "FurColor: "+dog.furColor);
}
}
}