Java 循环执行，而

我试着做一个循环，但是“{”符号阻止了所有打印行的重复，我想在用户输入完序列值后，循环会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);
    }
}

---

我不认为我得到了你想要的，但这样你可以运行程序，直到用户在程序的第一部分输入不同于“F”、“F”、“C”、“C”的内容

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);
    }
}

---

我已将其放入while循环中，并在“终止程序”部分添加了“break；”。

我没有看到循环。您可以编辑此内容以发布您尝试过的循环代码吗？您是认真地询问代码中没有单个循环的do-while循环吗？请尝试以下操作：“{”符号防止所有打印行重复”呃，不。是时候阅读旧的教程了。我想帮你找到你尝试过的方法的问题。为了让我更容易，你能用你尝试过的循环来发布这个东西，而不是其他的代码吗？如果你要在每个方法中实例化一个

扫描仪输入

，为什么

cin

{你用过符号吗？谢谢。有时候最简单的解决方案就是最好的。我一直在尝试一个“做一段时间”的语句，但那不起作用。没问题，我很高兴它帮了你的忙！谢谢你选择我的最佳答案，我真的很感激。