税务收入计划(如报关单)

Question

import java.util.Scanner;
public class CardenasE_IncomeTax {
    
    public static void main(String[] args) {
        String username = "CardenasE";
        String realpass = "CarErick12!";
        boolean isMarried = true;
        boolean isNotMarried = false;

        double tax1 = 0;
        double tax2 = 0;
        double tax3 = 0;

        double RATE1 = 0.10;
        double RATE2 = 0.12;
        double RATE3 = 0.22;
        double RATE4 = 0.24;
        double RATE5 = 0.32;

        double limitSingle1 = 10000;
        double limitSingle2 = 40000;
        double limitSingle3 = 90000;
        double limitSingle4 = 165000;


        double limitMarried1 = 20000;
        double limitMarried2 = 80000;
        double limitMarried3 = 170000;

        Scanner input = new Scanner(System.in);

        System.out.println("Username: ");
        String user = input.nextLine();

        System.out.println("Password:");
        String pass = input.nextLine();

        if (user.equals(username) && pass.equals(realpass)) {
            System.out.println("Login Successful!");
        } else if (!user.equals(username) || !pass.equals(realpass)) {
            System.out.println("Invalid Credentials!");
            return;
        }

        System.out.printf("%n What is your gross income?: ");
        double grossIncome = input.nextInt();

        System.out.println("Are you married?: (Type 's' for single and 'm' for married.) ");
        String maritalStatus = input.next();

        if (maritalStatus.equals("s")) {
            if (grossIncome <=limitSingle1)
                tax1 = grossIncome * RATE1;
            System.out.println("Your income is: " + tax1);
            return;
        } else if (grossIncome > limitSingle1 && grossIncome <= limitSingle2){
            tax2 = grossIncome * RATE2;
            System.out.println("Your income is: " + tax2);
        } 
    } 
}

当使用第一个限制(从0到10,000为10% )的括号时，它给出了正确的解，但我有另一个if语句，它大于10,000，但小于或等于40,000，它的设置为第一个if语句，但它给出了0作为答案，不管我加了多少个数字。

Answer 1

尝试将总收入中的else if块移到语句if (grossIncome <=limitSingle1)中嵌套的if中。如下所示：

    if (maritalStatus.equals("s")) {
        if (grossIncome <=limitSingle1) {
            tax1 = grossIncome * RATE1;
            System.out.println("Your income is: " + tax1);
        } else if (grossIncome > limitSingle1 && grossIncome <= limitSingle2) {
            tax2 = grossIncome * RATE2;
            System.out.println("Your income is: " + tax2);
        }  
        return;

我们可以通过删除tax1、tax2和tax3变量进一步改进您的代码，并且只有tax变量。这是为了减少重复打印出局。

    if (maritalStatus.equals("s")) {
        if (grossIncome <=limitSingle1) {
            tax = grossIncome * RATE1;
        } else if (grossIncome > limitSingle1 && grossIncome <= limitSingle2) {
            tax = grossIncome * RATE2;
        }  
        System.out.println("Your income is: " + tax);
        return;

作为最佳实践，如果你的价值观是不应该改变的。您应该添加final关键字以避免修改。

double final RATE1 = 0.10;

此外，您可以通过在Constants.java文件中移动常量来改进这一点。您也可以将其实现为HashMap来进行查找。