1java中子类不能调用父类的私有变量,以及其中调用的时候要用到super:
代码:
package firstcode;
import java.util.*;
public class My
{
public static void main()
{
System.out.print("123");
Manager boss = new Manager("carl",10000000,1994,1,2);
boss.setBonus(50000);
Employee[] staff = new Employee[1];
staff[0] = boss;
for(int i=0;i<staff.length;i++)
{
Employee e = staff[i];
System.out.println(e.getName()+" "+e.getSalary());
}
}
}
class Employee
{
public Employee(String n,double s,int year,int month,int day)
{
name = n;
salary = s;
GregorianCalendar calendar = new GregorianCalendar(year,month-1,day);
hireDay = calendar.getTime();
}
public String getName()
{
return name;
}
public double getSalary()
{
return salary;
}
public Date getHireDay()
{
return hireDay;
}
public void raiseSalary(double byPercent)
{
double raise = salary*byPercent/100;
salary += raise;
}
private String name;
private double salary;
private Date hireDay;
}
class Manager extends Employee
{
public Manager(String n,double s,int year,int month,int day)
{
super(n,s,year,month,day);
bonus = 0;
//super 调用必须是子类的第一条语句。
}
public void setBonus(double b)
{
bonus = b;
}
public double getSalary()
{
double baseSalary = super.getSalary();
return baseSalary+bonus;
//其中这样是不可以的 : return (salary+bonus)没法工作
//子类不能直接调用父类的私有字段。
//也不能 return (getSalary()+bonus),
//这里getSalary:就是无限的调用自己
}
private double bonus;
}