/** * Learn Java from https://www.liaoxuefeng.com/ *  * @author liaoxuefeng */public class Main {   public static void main(String[] args) {      // TODO: 给一个有工资收入和稿费收入的小伙伴算税:      Income[] incomes = new Income[] { new Income(3000), new SalaryIncome(7500), new RoyaltyIncome(12000) };      System.out.println();   }   public static double totalTax(Income... incomes){      double total = 0;      for(Income income:incomes){         total=total+income.getTax();      }      return total;   }}/** * 稿费收入税率是20% */public class RoyaltyIncome extends Income{   public RoyaltyIncome(double income)   {      super(income);   }   @Override   public double getTax() {      return income*0.2;   }}