//没有重写toString()方法的类

 class Person{

     private String name;

     //构造方法

     public Person(String name){

         this.name = name;

     }

 }

 //重写了toString()方法的类

 class Animal{

     private String kind = "cat";

     //重写的toString()方法  返回值为String

     public String toString(){

         return kind;

     }

 }

 //测试类

 public class PrintObject {

     public static void main(String[] args){

         //测试重写了toString()方法的类

         Person person = new Person("gxf");

         System.out.println(person);

         //测试没有重写toString()方法的类

         Animal animal = new Animal();

         System.out.println(animal);

     }

 }