person5.java

Java Classic Examples是我买的两本书：《JAVA经典实例》和《java入门经典源代码》里边附送光盘里带的源码

public class Person5
{
    static int count=0;
    protected String name; 
    protected int age;
    public Person5(String n1,int a1) 
    {
        name = n1;
        age = a1;
        count++;
    }
    public Person5(String n1)                //构造方法重载
    {
        this(n1,0);                          //调用本类的构造方法
    } 
    public Person5(int a1)                   //构造方法重载
    {
        this("未知名",a1);
    } 
    public Person5()                         //构造方法重载
    {
        this("未知名");
    } 
    public void print()
    {
        System.out.print(this.getClass().getName()+"  ");
        System.out.print("count="+this.count+"    ");
        System.out.println("  "+name+", "+age);
    }
}
class Student5 extends  Person5
{
    protected String dept;
    Student5(String n1,int a1,String d1) 
    {
        super(n1,a1);
        dept = d1;
    }    
    Student5() 
    {
        this("未知名",0,"未知系");
    }    
    public static void main(String args[])
    {
        Person5 p1 = new Person5("王小明",21) ; 
        p1.print();
        Person5 p2 = new Person5("朱小安") ; 
        p2.print();
        Person5 p3 = new Person5(19) ; 
        p3.print();
        Person5 p4 = new Person5() ; 
        p4.print();
        Student5 s1 = new Student5("陈小瑞",19,"计算机系");
        s1.print();
        Student5 s2 = new Student5();
        s2.print();
    }
}