java - 很难找到该范围是否为空，以便我继续编写代码。 java

Question

关闭。此题需要 details or clarity 。目前不接受答案。

---

想要改进这个问题吗？通过 editing this post 添加详细信息并澄清问题.

已关闭 3 年前。

Improve this question

    int[] intRange1 = {};
    intNum = getValidInt(sIn, "Please enter a whole number: ",
            "Invalid response. Only whole numbers are acceptable.", intRange1);
    System.out.println("The whole number your entered was: " + intNum);
    System.out.println("Now we will test your whole number in a math equation...");
    System.out.printf("Adding 10 to your whole number would be: 10 + %d = %d.\n\n", intNum, (intNum + 10));

    // Get an integer within a range from the user
    int[] intRange2 = { 10, 50 };
    intNum = getValidInt(sIn, "Please enter a whole number between 10 and 50: ",
            "Invalid response. Only whole numbers between 10 and 50 are acceptable.", intRange2);
    System.out.println("The whole number your entered was: " + intNum);
    System.out.println("Now we will test your whole number in a math equation...");
    System.out.printf("Adding 10 to your whole number would be: 10 + %d = %d.\n\n", intNum, (intNum + 10));
}
/*
 * making the method I can get it to validate the first part but I can not get
 * it to do the part with the range
 */

public static int getValidInt(Scanner sIn, String question, String warning, int[] range) {
    boolean valid = false;
    int validNumber = 0;

    do {
        System.out.println("Please enter a whole number: ");
        String number = sIn.nextLine();

        try {
            validNumber = Integer.parseInt(number);
            valid = true;
        } catch (NumberFormatException e) {

            System.out.println("Invalid response. Only whole numbers are acceptable.");
            valid = false;

        } // end of try/catch block
    } while (!valid);// end of do while
}

Answer 1

为什么不直接做

    int v = SIn.nextInt();

然后如果它不是整数则捕获异常。请尝试以下操作:

    Scanner sIn = new Scanner(System.in);


    int r = getValue(sIn, 10, 40);

    System.out.println("You entered " + r);

    static int getValue(Scanner sIn, int low, int high) {
      String msg = "Please enter a number between %d and %d%n";
      while (true) {
         System.out.printf(msg, low, high);
         System.out.print("Enter: ");
         try {
            int v = sIn.nextInt();
            if (v >= low && v <= high) {
               sIn.nextLine();//clear input buffer
               return v;
            }
            System.out.printf("Number out of range (%d).", v);
         }
         catch (InputMismatchException e) {
            System.out.printf("Illegal input type (%s)%n", sIn.nextLine());
         }
      }
    }