Ê®¶þ javaÃæÏò¶ÔÏó³ÌÐòÉè¼Æ(ÀàµÄ¼Ì³Ð)

Ê®¶þ javaÃæÏò¶ÔÏó³ÌÐòÉè¼Æ(ÀàµÄ¼Ì³Ð)
/**
 * ÀàµÄ¼Ì³Ð
 */
class Person
{
 private String name;
 private int age;
 public String setName(String name){this.name = name;return name;}
 public int setAge(int age){this.age = age;return age;}
 public void getInfo()
 {
  System.out.println("name = " + name + ", age = " + age);
 }
}
/*
class Student //StudentÀàÖظ´¶¨ÒåÁËPersonÀàµÄ·½·¨ºÍ³ÉÔ±±äÁ¿
{
 private String name;
 private int age;
 public String setName(String name){this.name = name;return name;}
 public int setAge(int age){this.age = age;return age;}
 public void getInfo()
 {
  System.out.println("name = " + name + ", age = " + age);
 }
 
 private String school;
 public String setSchool(String school){this.school = school; return school;}
 public void study()
 {
  System.out.println("study in " + school);
 }
}
*/
/**
 * 1,ͨ¹ý¼Ì³Ð¿ÉÒÔ¼ò»¯ÀàµÄ¶¨Òå ¡£
 */
class Student extends Person //ͨ¹ý¼Ì³Ð,ÕâЩÖظ´µÄ¶¨Ò彫±»Ê¡ÂÔ.
{
 private String school;
 public String setSchool(String school){this.school = school; return school;}
 public void study()
 {
  System.out.println("study in " + school);
 }
 
 public static void main(String[] args)
 {
  Person p1 = new Person();
  p1.setName("unknown");p1.setAge(0);
  //p1.setSchool("unknown");´íÎó,¸¸À಻ÄÜ·ÃÎÊ×ÓÀàµÄ³ÉÔ±.
  p1.getInfo();
  //p1.study();´íÎó,¸¸À಻ÄÜ·ÃÎÊ×ÓÀàµÄ³ÉÔ±.
  
  Person p2 = new Student();
  p2.setName("mike");
  p2.setAge(23);
  ((Student)p2).setSchool("Cambridge");
  p2.getInfo();
  ((Student)p2).study();
  //¸¸ÀàµÄ¶ÔÏó¿ÉÒÔÏòÏÂתÐÍ.
  
  Student s1 = new Student();
  s1.setName("jackson");