java温度转换程序不工作

Question

我有一个关于我正在参加的编程类(class)介绍的作业，我没有任何错误，但它仍然无法正常工作。作业是编写一个程序，将温度从摄氏度转换为华氏度，反之亦然。它还必须以不同的方法完成，然后必须循环一遍又一遍地完成。这部分是我现在遇到问题的地方。线

if(retry == y)

无法正常工作。提前致谢。

package cps101temperatureconverter;
import static 
cps101temperatureconverter.CPS101TemperatureConverter.enteredTemp;
import java.util.Scanner;

public class CPS101TemperatureConverter 
{

//char inputChoice;
int input;
static double enteredTemp;
static double calculatedTemp;
static char retry = 'y';
static Boolean moreToProcess = true;
static double fahrenheitTemp;
static double celsiusTemp;
Scanner keyboard = new Scanner(System.in);
static char c = 'C';
static char f = 'F';

public static void main(String[] args) 
{
    char inputChoice;
    Scanner keyboard = new Scanner(System.in);
    String inputTempString;
    String inputTypeString;
    String retryString;
    //char retry = 'y';

    do
    {


    System.out.println("This program will convert temperatures.");
    System.out.println("Please Enter a Temperature: ");
    inputTempString= keyboard.nextLine();
    enteredTemp = Double.parseDouble(inputTempString);
    System.out.println("You have entered " + enteredTemp);
    System.out.println("Is this value in (C)elsius or (F)ahrenheit? ");
    inputTypeString = keyboard.nextLine();
    inputChoice = inputTypeString.charAt(0);

    if (inputChoice == c)
    {
        CelsiusToFahrenheit();
    }
    else if (inputChoice == f)
    {
        FahrenheitToCelsius();
    }
    else
    {
        System.out.println("You have entered an invalid answer. Please try again.");
    }
    System.out.println("Would you like to convert another temperature? Enter yes or no. ");
    retryString = keyboard.nextLine();
    retry = retryString.charAt(0);
    if (retry == y)
    {
        moreToProcess = true;
    }
    else{
        moreToProcess = false;
    }
    }while(moreToProcess = true);

    System.out.println("The Program will terminate now.");

}

static void CelsiusToFahrenheit()
{
    calculatedTemp = (9.0/5.0)*enteredTemp + 32;
    System.out.println(enteredTemp + " converted to Fahrenheit is " + calculatedTemp);
}
static void FahrenheitToCelsius()
{
    calculatedTemp = (enteredTemp - 32)*(9.0/5.0);
    System.out.println(enteredTemp + " converted to Celsius is " + calculatedTemp);
}

}

Answer 1

简短的回答是您尚未初始化 c 或 f。它们只是静态 char 变量，但您必须给它们一个值来进行比较。

static char c = 'C';
static char f = 'F';

但请注意，此比较区分大小写；如果用户输入小写的 c 或 f 则不起作用。您应该尝试使您的程序更明确地了解它期望的输入。也许是这样的:

System.out.println("这个值是(C)elsius还是(F)ahrenheit吗？");