Java 乘法错误

Question

需要帮助解决这个问题。

似乎无法弄清楚为什么补贴保费打印为 0。

import java.util.Scanner; 

public class qns1b
{
    public static void main(String[]args)
    {
        Scanner kb = new Scanner(System.in); 
        System.out.print("Enter the age next birthday of the citizen: ");
        int age = kb.nextInt();
        System.out.print("Enter the annual value of residence: $ ");
        double annualValue = kb.nextDouble();
        System.out.print("Enter number of properties: ");
        int noOfProperties = kb.nextInt();
        System.out.print("Enter the monthly income: $ ");
        double monthlyIncome = kb.nextDouble();

        double subsidy = 0;

        double annualPremiumBfoSubsidy = 0;
        double annualPremium;
        double subsidisedPremium = 0;
        double subsidisedDeduction = 0;


        subsidisedDeduction = annualPremiumBfoSubsidy*subsidy; 
        subsidisedPremium =   annualPremiumBfoSubsidy-subsidisedDeduction;

        //(ii)

        if (age <= 20 && monthlyIncome <= 1100 && noOfProperties == 1)

        {
            subsidy = 0.25;
            annualPremium = 50;
            annualPremiumBfoSubsidy = 130;
            System.out.println("Previous Premium: $" +annualPremium+ " " + "Current Premium: $" +annualPremiumBfoSubsidy);
            System.out.println("Subsidised Premium: $" +subsidisedPremium+ " " +"(deduct $" +subsidisedDeduction+ "for 30% of" +annualPremiumBfoSubsidy+ ")");

        }
        else 
        {
            System.out.print ("good");
        }

}
}

Answer 1

它是两个设置为零的变量的差异。

 subsidisedPremium =   annualPremiumBfoSubsidy-subsidisedDeduction;

这两个变量之前都设置为零。