JAVA 将 double 添加到字符串

Question

我只是有一个关于在 JAVA 中添加一些货币 ($) 的问题，我使用了 NumberFormat.getCurrencyInstance();以“$”获取我的输出。我的程序是输入一些钱（字符串格式），例如程序只接受（$100.00、$50.00、$20.00 ... 等等）所以我使用了这个代码：

String payment = keyboard.next();
while (!(payment.equals("0.00")) && (!payment.equals(".00")) && (!payment.equals(".00")) && (!payment.equals(".00")) && (!payment.equals(".00")) && (!payment.equals(".00")) && (!payment.equals(".00")) {
System.out.print("Invalid coin or note. Try again. ");
payment = keyboard.next(); }

如何将输入 (100.00, 50.00 ...) 作为 Double 获取，以便从总价中减去它们.. 例如我要 (100.00-12.00) (12.00 是总价)

如有任何帮助，我们将不胜感激谢谢

Answer 1

public double convertPayment(String inputPayment) {   
    String payment = inputPayment.substring(1);
    double paymentValue = Double.parseDouble(payment);
    return paymentValue;
}

Answer 2

如果您输入的是“$”符号，您可以删除字符串的第一个元素，然后将其转换为双精度。

//method to convert String in Double
public Double getDoubleFromString(String payment) 
{
  payment = payment.substring(1);
  double paymentDouble = Double.parseDouble(payment);
  return paymentDouble;
}

String payment = keyboard.next();
double paymentDouble = getDoubleFromString(payment);

while (paymentDouble != 100.00 && paymentDouble != 50.00 && paymentDouble != 20.00 
           && paymentDouble != 10.00 && paymentDouble != 5.00 
           && paymentDouble != 2.00 && paymentDouble != 1.00) 
      {
         System.out.print("Invalid coin or note. Try again.");
         String payment = keyboard.next();
         paymentDouble = getDoubleFromString(payment);
      }

JAVA 将 double 添加到字符串

JAVA adding double to a string

java

string

double