Object类——toString()方法


package e5_2;

public class ToStringDemo {

 public static void main(String[] args) {

  Student s = new Student("Tom", 26);

  GraduateStudent g = new GraduateStudent("jim", 26);

  System.out.println(s);

  System.out.println(g);

 }

}

class Student{

 

 String name;

 int age;

 public Student(String name, int age){

  this.name = name;

  this.age = age;

 }

}

class GraduateStudent extends Student{

 public GraduateStudent(String n, int a){

  super(n, a);

 }

 

 public String toString(){

  return name + " " + age + " ";

 }

}

Student类没有覆盖toString（）方法，所以s显示的是类名@内存地址，而GraduateStudent覆盖了toString（）方法，所以g显示出来的信息更有意义。