java - 为什么我的循环运行时间比我想要的少一次？

Question

对于类(class)，我应该编写一个数字扫描仪来打印用户输入、这些数字的总和和乘积。我们可以假设用户在每个数字后输入一个空格，并且用户可以输入任意数量的数字。例如:3 10 2 您的号码是: 3 10 2 总数:15 产品数量:60

public static void substringGrabber () {
    String recentInt;
    int lastDigit = 0;
    int parsedInt = 0;
    for (int i = 0; i < numbers.length(); i++) {
        if (! Character.isDigit(numbers.charAt(i))) {
            char ignoredCharacter = numbers.charAt(i);
            if (ignoredCharacter != ' ') {
                System.out.println("Your input of:" + ignoredCharacter + " has been ignored");
            }
            recentInt = numbers.substring(lastDigit, i);
            parsedInt = Integer.parseInt(recentInt);
            sum += parsedInt;
            product *= parsedInt;
            lastDigit = i + 1;
            finalString = finalString + parsedInt + " ";

        }

    }

    System.out.println("Your numbers are: " + finalString);
    System.out.println("Sum: " + sum);
    System.out.println("Product: " + product);
}

Answer 1

默认情况下，驻留在 Scanner 中的

nextInt() 使用空格作为标记分隔符。因此，您的代码可以如下所示(提前询问他们要输入多少数字):

System.out.println("How many numbers?");
int numbers = scanner.nextInt();
int sum = 0;
int product = 0;
int[] arr = new arr[numbers];
for (int i = 0; i < numbers; i++){
    System.out.println("Type in a number");
    int input = scanner.nextInt();
    sum += input;
    arr[i] = input;
    product *= input;
}

System.out.println("Your numbers are: " + Arrays.deepToString(arr));
System.out.println("Sum: " + sum);
System.out.println("Product: " + product);