循环 - 做，而

Question

我试着做一个循环，但“{”符号防止所有的打印行重复我认为。我希望循环在用户完成输入序列值后重新显示整个第一个字符串。

import java.util.Scanner; 

public class FtoC{ 

    static Scanner cin = new Scanner (System.in); 

    public static void main(String[] args) 
    { 
     char userInput = ' '; 
     System.out.print("\nEnter " + "\"F\"" + " or " + "\"f\"" + " for Fahrenheit to Celsius" 
         + "\nEnter " + "\"C\"" + " or " + "\"c\"" + " for Celsius to Fahrenheit" 
         + "\nEnter something else to quit." +"\n"); 


     userInput = cin.next().charAt(0); 

     if ((userInput == 'F') || (userInput =='f')) 
     {print("Enter a temp in Fahrenheit" 
       +"\n I will tell you temp in Celsius" +"\n"); 
      far2cel(); 
     } 
     else if ((userInput == 'C') || (userInput =='c')) { 
      print("Enter a temp in Celsius:" 
      +"\n I will tell you temp in fahrenheit" +"\n"); 
       cel2far(); 
     } else { 
      print("Terminating the program" + "\n"); 
     } 
    } 

    private static void cel2far() { 
     Scanner input = new Scanner(System.in); 
     Double celsius = input.nextDouble(); 
     print(celsius + " celsius is " + ((celsius * 9/5.0) + 32) 
       + " Fahrenheit"); 

    } 

    private static void far2cel() { 
     Scanner input = new Scanner(System.in); 

     Double Fahrenheit = input.nextDouble(); 
     print(Fahrenheit + " Fahrenheit is " + ((Fahrenheit - 32) * (5/9.0)) 
       + " celsius"); 

    } 

    private static void print(String string) { 
     System.out.print("\n" + string); 
    } 
} 

Answer 1

我不认为我得到你想要什么，但这样一来就可以运行该程序，直到用户输入的东西比“F”，“F”，“C”，“C”，在不同的该计划的第一部分。

import java.util.Scanner; 

public class FtoC{ 

    static Scanner cin = new Scanner (System.in); 

    public static void main(String[] args) 
    { 
     while(true) { 
      char userInput = ' '; 
      System.out.print("\nEnter " + "\"F\"" + " or " + "\"f\"" + " for Fahrenheit to Celsius" 
          + "\nEnter " + "\"C\"" + " or " + "\"c\"" + " for Celsius to Fahrenheit" 
          + "\nEnter something else to quit." +"\n"); 

      userInput = cin.next().charAt(0); 

      if ((userInput == 'F') || (userInput =='f')) 
      {print("Enter a temp in Fahrenheit" 
        +"\n I will tell you temp in Celsius" +"\n"); 
       far2cel(); 
      } 
      else if ((userInput == 'C') || (userInput =='c')) { 
       print("Enter a temp in Celsius:" 
       +"\n I will tell you temp in fahrenheit" +"\n"); 
        cel2far(); 
      } else { 
       print("Terminating the program" + "\n"); 
       break; 
      } 
     } 
    } 

    private static void cel2far() { 
     Scanner input = new Scanner(System.in); 
     Double celsius = input.nextDouble(); 
     print(celsius + " celsius is " + ((celsius * 9/5.0) + 32) 
       + " Fahrenheit"); 

    } 

    private static void far2cel() { 
     Scanner input = new Scanner(System.in); 

     Double Fahrenheit = input.nextDouble(); 
     print(Fahrenheit + " Fahrenheit is " + ((Fahrenheit - 32) * (5/9.0)) 
       + " celsius"); 

    } 

    private static void print(String string) { 
     System.out.print("\n" + string); 
    } 
} 

我已将它放入while循环并添加“break”在“终止程序”部分。