23.多态实例

基础班的学生：
　　学习，睡觉
高级班的学生：
　　学习，睡觉
可以将这两类事物进行抽取

public class DuoTai_03 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		DoStudent ds=new DoStudent();
		ds.doSomething(new BaseStudent()); //Students s=new BaseStudent(); 
		ds.doSomething(new AdvStudent());
	}
	

}
class DoStudent{
	public void doSomething(Students s){
		s.study();
		s.sleep();
	}
}
abstract class Students{
	public abstract void study();
	public void sleep(){
		System.out.println("躺着睡");
	}
}
class BaseStudent extends Students{
	public void study(){
		System.out.println("base study");
	}
	public void sleep(){
		System.out.println("坐着睡");
	}
}
class AdvStudent extends Students{
	public void study(){
		System.out.println("adv study");
	}
}