package a; public class Student{ private int age; private String name; public Student(String name,int age){ this.name=name; this.age=age; } public String toString(){ return this.name+this.age; } public static void main(String[] args){ Student s=new Student("张三",23); s.name="zhang"; System.out.println(s); } } 关于上述代码说明正确的是