为什么我的循环运行的时间比我想要的少？

Question

For class I am supposed to write a number scanner that prints user input, the sum and product of these numbers. We can assume the user enters a space after every number and the user may enter as many numbers as they'd like. Ex: 3 10 2 Your numbers are: 3 10 2 Sum: 15 Product: 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

nextInt() which resides in Scanner by default uses white-space as a token separator. Therefore, your code can look like this (ask them in advance how many numbers they're going to type in):

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);

Answer 2

If you add a space at the end of your test string it will work.

this check !Character.isDigit(numbers.charAt(i)) ignores the last digit.

so change the logic to account for that that case : you have a digit and you are at the end of your string.