public class Main {    public static void main(String[] args) {        // 给一个有工资和稿费的小伙伴算税:        Salary[] salaries = new Salary[] {                new Salary(8000),                new Royalties(5000)        };        System.out.println(totalTax(salaries));    }    public static double totalTax(Salary... salaries) {        double total = 0;        for (Salary salary: salaries) {            total = total + salary.getTax();        }        return total;    }}class Salary {    protected double salary;    public Salary(double salary) {        this.salary = salary;    }    public double getTax() {        if (salary < 5000){            return 0;        }        return (salary-5000)*0.2;    }}class Royalties extends Salary{    public Royalties(double salary){        super(salary);    }    @Override    public double getTax() {        return salary*0.3;    }}