java - Java:如何测试输入是 double 还是整数

我有一个do while循环。检查x在两个值之间。现在，我应该输入一个int值，但是如果用户键入一个double，则会获取异常。我如何在同一个if语句中合并一个检查，以便如果用户键入一个双精度字，它会打印类似“ x必须是介于10和150之间的整数”的内容：

            do {
            x = sc.nextInt();
            if ( x < 10 || x > 150 ) {
                System.out.print("x between 10 and 150: ");
            } else {
                break;
            }

最佳答案

您可以使用while (true)捕获异常并对其进行处理，以允许用户重试。

这是我的代码：

Scanner sc = new Scanner(System.in);
do {
    System.out.print("\nInsert a number >>> ");
    try {
        int x = sc.nextInt();
        System.out.println("You inserted " + x);
        if (x > 10 && x < 150) {
            System.out.print("x between 10 and 150: ");
        } else {
            break;
        }
    } catch (InputMismatchException e) {
        System.out.println("x must be an int between 10 and 150");
        sc.nextLine(); //This line is really important, without it you'll have an endless loop as the sc.nextInt() would be skipped. For more infos, see this answer http://stackoverflow.com/a/8043307/1094430
    }
} while (true);