无法追踪 java.lang.ArrayIndexOutOfBoundsException：

Question

我正在尝试解决以下简单的编程练习："Write a program that reads the integers between 1 and 10 and counts the occurrences of each. Assume the input ends with 0"。我想出了以下解决方案。我不熟悉调试器并尝试跟踪 ArrayIndexOutOfBoundsException 最后 3 个小时。也许有人能够看到 ArrayIndexOutOfBoundsException 发生的地方？

import java.util.Scanner;

public class Exercise07_03 {
    /** Main method */
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        int[] numbers = new int[10];
        System.out.print("Enter up to 10 integers between 1 and 10" + 
            "inclusive (input ends with zero): ");

        int i = 0;
        do {
            numbers[i] = input.nextInt();
            i++;
        } while (numbers[i] != 0 && i != 9);

        displayCounts(countNumbers(numbers));
    }

    /** Count the occurrences of each number */
    public static int[] countNumbers(int[] numbers) {
        int[] counts = new int[10];

        for (int i = 0; i < counts.length; i++)
            counts[numbers[i] - 1]++;

        return counts;
    }

    /** Display counts */
    public static void displayCounts(int[] counts) {
        for (int i = 1; i < counts.length + 1; i++)
            if (counts[i - 1] != 0)
                System.out.println(i + " occurs " + counts[i - 1] + " time");
    }
}

Answer 1

         counts[numbers[i] - 1]++;

如果输入包含 0，则结果为 -1。

Answer 2

问题出在这里：

public static int[] countNumbers(int[] numbers) {
    int[] counts = new int[10];

    for (int i = 0; i < counts.length; i++)
        counts[numbers[i] - 1]++;

    return counts;
}

解决方案在：

 counts[(number - 1 > 0) ? number - 1 : 0]++;

这会检查 (number-1) 是否大于零。如果不是，则使用 0。如果为真，则使用数字 -1。

无法追踪 java.lang.ArrayIndexOutOfBoundsException：

Can't trace an java.lang.ArrayIndexOutOfBoundsException:

java

debugging