java - 需要帮助格式化 switch 方法调用的输出

Question

这是针对我正在学习的类(class)，我们被指示创建一个具有两个参数(价格和状态)的方法，然后让用户输入任何价格，该方法将针对该价格运行并输出成本来自多个州。我为自己弄清楚如何让它大部分发挥作用而感到非常自豪。但是，有几个小问题需要帮助解决。

• 仅当我输入整数时才有效
• 超过两位小数位
• 即使我没有要求它，它也会显示“case”值。

在展示我的代码之前，这里是一个示例输出。

输入 donut 的价格:
5
这是每个州的费用
肯塔基州-5.3
凯
哦 - 5.2875
哦
IN - 5.35
在
TN - 5.35
tn
佛罗里达州 - 5.3
FL
WF-5.3
wf

    import java.util.Scanner;
public class TaxCalculator {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("Enter price of donut: ");
        double price = input.nextInt();
        String[] state=new String[6];
        state[0]="ky";
        state[1]="oh";
        state[2]="in";
        state[3]="tn";
        state[4]="fl";
        state[5]="wv";

        System.out.println("Here's how much your donut would cost in each state");
        System.out.println(addTax(price,state[0]));
        System.out.println(addTax(price,state[1]));
        System.out.println(addTax(price,state[2]));
        System.out.println(addTax(price,state[3]));
        System.out.println(addTax(price,state[4]));
        System.out.println(addTax(price,state[5]));
    }


public static String addTax( double price, String state ) {
    switch (state) {
    case "ky": System.out.println("KY - " + ((price*.06)+price));   
        break;
    case "oh": System.out.println("OH - " + ((price*.0575)+price));
        break;
    case "in": System.out.println("IN - " + ((price*.07)+price));
        break;
    case "tn": System.out.println("TN - " + ((price*.07)+price));   
        break;
    case "fl": System.out.println("FL - " + ((price*.06)+price));
        break;
    case "wv": System.out.println("WV - " + ((price*.06)+price));
        break;
    default: System.out.println("Invalid");
    break;
            }
    return state;
    }
}

谢谢大家!我结合了您的很多建议并得到了我所需要的。我喜欢这个地方。

import java.text.DecimalFormat;
import java.util.Scanner;
public class TaxCalculator {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.println("Enter price of donut: ");
        double price = input.nextDouble();
        String[] state=new String[6];
        state[0]="ky";
        state[1]="oh";
        state[2]="in";
        state[3]="tn";
        state[4]="fl";
        state[5]="wv";

        System.out.println("Here's how much your donut would cost in each state");
        addTax(price,state[0]);
        addTax(price,state[1]);
        addTax(price,state[2]);
        addTax(price,state[3]);
        addTax(price,state[4]);
        addTax(price,state[5]);
    }


public static String addTax( double price, String state ) {
    String result=("");
    DecimalFormat money=new DecimalFormat("$#,###.00");
    switch (state) {
    case "ky": System.out.println("KY - " + money.format((price*.06)+price));   
        break;
    case "oh": System.out.println("OH - " + money.format((price*.0575)+price));
        break;
    case "in": System.out.println("IN - " + money.format((price*.07)+price));
        break;
    case "tn": System.out.println("TN - " + money.format((price*.07)+price));   
        break;
    case "fl": System.out.println("FL - " + money.format((price*.06)+price));
        break;
    case "wv": System.out.println("WV - " + money.format((price*.06)+price));
        break;
    default: System.out.println("Invalid");
    break;
            }

    return state;

    }
}

Answer 1

而不是:

System.out.println(addTax(price,state[0]));
    case "ky": System.out.println("KY - " + ((price*.06)+price));   
            break;
    return state; 

这样做:

System.out.printf("%.1d", addTax(price,state[0]));
     case "ky": String result = "KY - " + ((price*.06)+price);   
                break;
        return result;

或者类似的东西。这也是您在返回状态时打印状态并每次调用两次 System.out.println 的原因。调用 Double.parseDouble 而不是 Integer.parseInt 即可输入 double 。