While 循环确定输入的值是否为双精度值 [英] While loop to determine if entered value is a double

问题描述

我正在处理一个相当大的项目，这只是包含在其中.基本上，我创建了一个获取员工信息的类，我们需要它，以便用户必须输入双倍的工资率.说 8.00.请注意，用户不能添加美元符号，例如 $8.00，否则会提示用户发生错误.然而，当我测试运行代码时，没有使用错误提示，代码只是崩溃.

I'm working on a rather larger project and this is just included in it. Basically I created a class that takes an employee's info, we need to have it so the user must enter in a double for their pay rate. Say 8.00. Note the user CANNOT add in a dollar sign such as $8.00, else it will prompt the user an error has occured. Yet when I test run the code, instead of using the error prompt, the code simply crashes.

public static double getPayRate()
 {
    double payRate;
    System.out.println("Please enter the employee's pay rate (a numeric value): ");
    payRate = console.nextDouble();
    while(console.hasNextDouble())
    {
        System.out.println("An error occured with your input...");
        System.out.println("Please enter the employee's pay rate (a numeric value): ");
        payRate = console.nextDouble();
    }
    return payRate;
 }
}

推荐答案

好的，所以使用您拥有的代码，解决这个问题的方法就是这样..虽然此代码可用于检索 double 值，但不建议在处理金钱时使用 double，有关更多信息，请参阅此帖子.为什么不使用 Double 或 Float 来表示货币?

Okay so using the code you have, a way to go about this is like so.. While this code works to retrieve a double value, it is not recommended to use double when dealing with money, refer to this post for more information. Why not use Double or Float to represent currency?

import java.util.Scanner;

public class SOTest {

    public static Scanner console = new Scanner(System.in);

    public static double getPayRate()
     {
        while(true)
        {
            System.out.println("Please enter the employee's pay rate (a numeric value):");
            try {
                return Double.parseDouble(console.nextLine());
            } catch(NumberFormatException ex) {
                System.out.println("An error occured with your input...");
            }
        }
     }

    public static void main(String[] args) {
        System.out.println(getPayRate());
    }
}

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