Question

我正在创建一个银行帐户计划，我正在制作它以便余额总是以美元计算，但问题是我并不完全知道如何将这些方法结合在一起。这是我的一些代码。我想问的是转换器方法如何获取switch语句中使用的值？我尝试了多种不同的方法，但我总是有范围问题或重复变量。

public static double convertCurrency(double amount, int currencyType, boolean isConvertToUSD){
    //  checks what type of currency was chosen and converts each it into US dollars

    }
}

public static int currencyMenuOptionSelector(Scanner console){
    while(true){
        System.out.println("Please select the currency type:");
        System.out.println("1. U.S. Dollars");
        System.out.println("2. Euros");
        System.out.println("3. British Pounds");
        System.out.println("4. Indian Rupees");
        System.out.println("5. Australian Dollars");
        System.out.println("6. Canadian Dollars");
        System.out.println("7. Singapore Dollars");
        System.out.println("8. Swiss Francs");
        System.out.println("9. Malaysian Ringgits");
        System.out.println("10. Japanese Yen");
        System.out.println("11. Chinese Yuan Renminbi");
        int currencyType = console.nextInt();

        switch (currencyType){
        // cases 1-11 simply establishes each currency as a variable (not all cases are listed to avoid redundancy)
        case 1: {
            double USA = 1.00;
        }
        case 2: {
            double Euro = 0.89;

default: {
            System.out.println("Input failed validation. Please try again.");
            continue;
         }
        }


        }

    }

Answer 1

您可能应该将开关移到另一个方法，因为这是计算发生的地方。

您似乎走在正确的道路上，但需要提示转换金额。

System.out.print("Enter the type of currency: ");
int currencyType = Integer.parseInt(console.nextLine());

System.out.print("Enter currency amount: ");
double amount = Double.parseDouble(console.nextLine());

if (currencyType < 1 || currencyType > 11) {
    // TODO: Handle invalid input.
}

boolean toUSD = currencyType == 1;
double convertedAmount = convertCurrency(amount, currencyType, toUSD);

你的案件中需要break;。

Answer 2

这是我的代码。您可以尝试并告诉我它是否符合您的要求。

范围问题或重复变量。

你见面可能是因为你没有写回复陈述或＆＃34;打破＆＃34;如果任何开关盒匹配。

public class ConverTest {

public static double convertCurrency(double amount, int currencyType, boolean isConvertToUSD){
    //  checks what type of currency was chosen and converts each it into US dollars

    System.out.println("the input type:" + currencyType); //you say you want to get the values used in my switch
    // statement.
    return 0.01; //i don't know what u want to do in this meshod.
}

public static void main(String[] args) {
    Scanner in = new Scanner(System.in);
    convertCurrency(100.0, currencyMenuOptionSelector(in), true);
}

public static int currencyMenuOptionSelector(Scanner console) {

    while (true) {
        System.out.println("Please select the currency type:");
        System.out.println("1. U.S. Dollars");
        System.out.println("2. Euros");
        System.out.println("3. British Pounds");
        System.out.println("4. Indian Rupees");
        System.out.println("5. Australian Dollars");
        System.out.println("6. Canadian Dollars");
        System.out.println("7. Singapore Dollars");
        System.out.println("8. Swiss Francs");
        System.out.println("9. Malaysian Ringgits");
        System.out.println("10. Japanese Yen");
        System.out.println("11. Chinese Yuan Renminbi");
        int currencyType = console.nextInt();
        switch (currencyType) {
        // cases 1-11 simply establishes each currency as a variable (not all cases are listed to avoid redundancy)
        case 1: {
            double USA = 1.00;
            return currencyType;
        }
        case 2: {
            double Euro = 0.89;
            return currencyType;
        }

            default: {
                System.out.println("Input failed validation. Please try again.");
                continue;
            }
        }

        }

    }
}

我无法将这两种方法放在一起

2 个答案: