Question

重复温度编程项目，添加允许的循环用户继续进入温度，直到他们输入Q或 q退出程序的那一部分。用户应输入Q或q 退出并返回一个空字符串以继续。（任何其他条目应该导致要重复的问题）如果用户输入不同的字母对于温度，用F或C（大写或小写），打印一个错误消息并要求用户输入正确的温标没有要求新的数值。

这就是我到目前为止......我无法理解它们是否输入65D而不是65C。如果他们输入D代替F / f或C / C，我无法弄清楚如何将其循环回代码......

import java.util.Scanner;
public class AssignmentFour {
public static Scanner keyboard = new Scanner(System.in);
public static void main(String[] args) {
    // TODO Auto-generated method stub

    System.out.println("Hello, I can convert Fahrenheit to Celsius!");
    System.out.println("Please enter the temperature you want converted.");
    System.out.println("Followed by: 'C/c' or 'F/f'");

    String input2 = keyboard.next();

    do{
        String temp = input2.trim();
        String degreesAsString = temp.substring(0, temp.length()-1);
        double degrees = Double.parseDouble(degreesAsString);

        if(temp.endsWith("C") || temp.endsWith("c")){            
            double degreeF = 9 * degrees / 5 + 32;
            System.out.println(input2 + " is equal to: ");
            System.out.printf("%.2f", degreeF);
            System.out.println(" Fahrenheit.");

        } else if(temp.endsWith("F") || temp.endsWith("f")){
            double degreeC = 5 * (degrees - 32) / 9;
            System.out.println(input2 +" is equal to: ");
            System.out.printf("%.2f", degreeC);
            System.out.println(" Celsius.");

        } else if (temp.endsWith(""));{
            System.out.println("ERROR: Please enter either 'F/f or C/c'.");     
        }
        break;
    } while(!input2.equals(""));

    System.out.println("");
}

Answer 1

只需在您的do-while循环内移动... = keyboard.next()，即可在您循环播放时读取新的用户输入。此外，您应该删除当前正在阻止的break;语句循环要完成。

Answer 2

请考虑以下其他方法。

package lala;
import java.util.Scanner;  
public class AssignmentFour {
public static Scanner keyboard = new Scanner(System.in);
public static void main(String[] args) {
// TODO Auto-generated method stub

System.out.println("Hello, I can convert Fahrenheit to Celsius!");
System.out.println("Please enter the temperature you want converted.");
System.out.println("Followed by: 'C/c' or 'F/f'");

String input2 = keyboard.next();

do{
    String temp = input2.trim();
    System.out.println(temp);
    String degreesAsString = deg(temp);
    System.out.println(degreesAsString);
    double degrees = Double.parseDouble(degreesAsString);

    if(temp.endsWith("C") || temp.endsWith("c")){            
        double degreeF = 9 * degrees / 5 + 32;
        System.out.println(input2 + " is equal to: ");
        System.out.printf("%.2f", degreeF);
        System.out.println(" Fahrenheit.");

    } else if(temp.endsWith("F") || temp.endsWith("f")){
        double degreeC = 5 * (degrees - 32) / 9;
        System.out.println(input2 +" is equal to: ");
        System.out.printf("%.2f", degreeC);
        System.out.println(" Celsius.");

    }else if(temp.equals("q") || temp.equals("Q")){

    } else{
        System.out.println("ERROR: Please enter either 'F/f or C/c'.");     
    }
    System.out.println("\nProvide new temperature:");
    input2=keyboard.next();
} while(!input2.equals(""));

System.out.println("");
}

public static String deg(String s){
if(s==null || "".equals(s)) return "";
StringBuilder sb = new StringBuilder();
for(int i=0;i<s.length();i++){
    if(Character.isDigit(s.charAt(i))) sb.append(s.charAt(i));
}
System.out.println(sb.toString());
return sb.toString();
}
}

温度错误的用户输入

2 个答案: