java - 我无法将这两种方法联系在一起

Question

我正在创建一个银行帐户程序，并且我正在制作它，以便余额始终以美元为单位，但问题是我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，但总是遇到范围问题或重复的变量。

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至其他方法，因为这是进行计算的地方。

您似乎走在正确的道路上，但需要提示输入要转换的金额。

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);

并且您的案例中需要 break;。