instanceofdemo.java

来自「这是清华大学编写的JAVA教材中所有题目的源代码！」· Java 代码 · 共 59 行

class Person 
{
  String name; //姓名
  int age;     //年龄

  Person(String n, int a)
  { name = n;  age = a;  }
}

class Student extends Person 
{
   int number;//学号

   Student(String n,int a,int no)
   {
      super(n,a);      
      number = no; 
   }
}

class Teacher extends Person 
{
   String empClass;//职称

   Teacher(String n,int a,String c)
   {
      super(n,a);      
      empClass = c; 
   }
}

public class InstanceOfDemo
{
	static void display(Person p)
	{ 
		System.out.println("姓名："+p.name);
		System.out.println("年龄："+p.age);
		
		if( p instanceof Student)
		{
			Student s=(Student)p;	
			System.out.println("学号："+s.number);
		}
		else if( p instanceof Teacher)
		{
			Teacher t=(Teacher)p;
			System.out.println("职称："+t.empClass);
		} 
	}
	
	public static void main(String args[])
	{
		Student s=new Student("John",20,101);
		display(s);
		
		Teacher t=new Teacher("Tom",40,"副教授");
		display(t);
	}
}