java - Java中调用后输入函数得到错误的值？

Question

我有一个问题是，当我为数组 2d 输入值且值有效时，一切都已完成，但是当我为 TotalRow 或 TotalColumn 变量输入错误值时，我的输入函数迫使我输入 double 并在第二个中获取值。这是我的代码:

public static void input() {
    Scanner sc = new Scanner(System.in);
    try {
        System.out.println("Input total totalRow: ");
        totalRow = sc.nextInt();
        // verify value input must be a positive integer and greater than zero
        if (totalRow <= 0) {
            System.out.println("Input value must be a positive integer and greater than zero!");
            input();
        }

        System.out.println("Input total totalColumn: ");
        totalColumn = sc.nextInt();
        // verify value input must be a positive integer and greater than zero
        if (totalRow <= 0) {
            System.out.println("Input value must be a positive integer and greater than zero!");
            input();
        }

        // check case array must be square array
        if (totalRow != totalColumn) {
            System.out.println("Array must be square!");
            input();
        }
    } catch (InputMismatchException e) {
        // print message when user input other than integer
        System.out.println("Please input an integer!");
        input();
    }

    // initialize array with totalRow and totalColumn
    array = new char[totalRow][totalColumn];

    // input value for array
    for (int i = 0; i < totalRow; i++) {
        for (int j = 0; j < totalColumn; j++) {
            array[i][j] = sc.next().charAt(0);
        }
    }
}

示例:我为totalRow和totalColumn输入2和a:出现消息，我重新输入是2和2，但我为数组输入了1 2 3 4 5 6 7 8，并且值从5获取。

Answer 1

这里有几件事导致您的代码失败:

1. 错字:您正在检查totalRow <= 0两次(复制粘贴肯定错误)

2. 如果条件不满足，则再次调用输入:这样做会递归实现该方法，这可能会导致序列的不期望的重复，让用户和开发人员发疯

3. 您忘记了 Scanner.nextInt 不会消耗输入的最后一个换行符

我建议通过执行以下操作来修改代码:

if (totalRow <= 0) {
        System.out.println("Input value must be a positive integer and greater than zero!");
        //input();
        }

        System.out.println("Input total totalColumn: ");
        totalColumn = sc.nextInt();
        sc.nextLine();
        // verify value input must be a positive integer and greater than
        // zero
        if (totalColumn <= 0) {
        System.out.println("......