java - 用户输入温度不正确

Question

Repeat the temperature programming project adding a loop that allows the user to continue entering in temperatures, until they enter a Q or q to exit that portion of the program. The user should enter a Q or q to exit and an empty String to continue. (Any other entry should cause the question to be repeated) If the user enters a different letter that F or C(either upper or lower case) for the temperature, print an error message and ask the user to enter the correct temperature scale without asking for a new numeric value.

这是我到目前为止所拥有的......我无法让它读取他们是否输入了 65D 而不是 65C。如果他们输入 D 而不是 F/f 或 C/c，我不知道如何在代码中循环它...

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

只需将 ... = Keyboard.next() 移动到 do-while 循环内即可在循环时读取新的用户输入。此外，您应该删除 break ; 语句当前只是阻止执行任何循环。