轉換溫輻射

Question

* java的幫助，因此，如果任何人能幫助我不知道什麼是錯我想我需要一段時間的狀態意味着 它不斷給我上else語句*

import java.util.*; //for class Scanner 
    public class Tempconversion 
    { 
     public static void main(String[] args){ 
     Scanner reader = new Scanner(System.in); 

     double F = 0; 
     double C = 0; 
     int ConvertFer = 0; 
     int ConvertCel = 1; 
     int Done = 3; 
      System.out.println("Welcome to the Temperature Converter!\n" + 
          "Enter 0 to convert F --> C and 1 to convert from C --> F.\n" + 
          "Enter 3 when done"); 

     if (ConvertFer == 0) 
      System.out.println("Welcome to the F --> C Converter\n"+ 
          "Enter Values to convert:"); 
      C = reader.nextDouble(); 
      F = ((F - 32)*5)/9; 
      System.out.println(F + "F = " + C + "C."); 


     else 
      System.out.println("Welcome to the C --> Fconverter\n"+ 
          "Enter Values to convert:"); 

      F = reader.nextdouble(); 
      C = ((C * 90)/5))+32; 
      System.out.println(C + "C =" + F +"F."); 

     } 
     } 

Answer 1

public static void main(String[] args) { 
    Scanner reader = new Scanner(System.in); 

    double tF = 0.0001; 
    double tC = 0.0001;   
    int convertFer = 0; 
    int convertCel = 1; 

    System.out.println("Welcome to the Temperature Converter!\n" 
      + "Enter 0 to convert F --> C and 1 to convert from C --> F.\n" 
      + "Enter Control-Z when done!"); 

    convertFer = reader.nextInt(); 

    if (convertFer == 0) { 
     System.out.println("Welcome to the F --> C Converter!\n" + "Enter Values to convert:"); 
     while (reader.hasNext()){ 

     tC = reader.nextDouble(); 

     tF = ((tC - 32) * 5)/9; 
      System.out.println(tC +" F = " + tF + " C");} 

    } else { 
     System.out.println("Welcome to the C --> F Converter!\n" + "Enter Values to convert:"); 
     while (reader.hasNext()){ 

     tF = reader.nextDouble(); 

     tC = ((tF * 9)/5) + 32; 
      System.out.println(tF + "C = " + tC + " F");} 

     System.out.println("Goodbye!"); 
     System.exit(0);  
    }  
} 

Answer 2

我認爲錯誤你缺少大括號在你的if/else聲明

if (ConvertFer == 0) { 
     // convert to F 

    } 
    else { 
    // convert to C 
    } 

而且，你if/else語句之前應閱讀的用戶選擇。您可能還需要循環代碼，以便您可以多次

public static void main(String[] args) { 
    Scanner reader = new Scanner(System.in); 

    double F = 0; 
    double C = 0; 
    int ConvertFer = 0; 
    int ConvertCel = 1; 
    int Done = 3; 
    System.out.println("Welcome to the Temperature Converter!\n" + 
         "Enter 0 to convert F --> C and 1 to convert from C --> F.\n" + 
         "Enter 3 when done"); 

    int userChoice = -1; 
    while(true) { 
     userChoice = reader.nextInt(); // read user choice 
     if(userChoice == ConvertFer) { 
      // convert to F 
     } else if(userChoice == ConvertCel) { 
      // convert to C 
     } else if (userChoice == Done) { 
      break; // finish the loop 
     } else { 
      System.out.println("Please enter a valid choice"); 
     } 
    } 
} 

注意做這種轉換也使他們能夠從類中容易區分不應按照慣例利用你的變量。您應該將變量重命名爲convertFer，convertCel和done