Question

我在运行时遇到错误：“索引数组越界”，我无法找到它。该程序假设取25个随机数，将它们分成偶数和奇数，并显示单独的组。我调试了第一个for语句，很好，它是我的第二个，但我不知道为什么。我可以没有两个相等的数组元素吗？

public class EvensandOdds {



 public static void main(String[] args)  {

    int i;
    int countEven = 0;
    int countOdd = 0;
    int num;
    int numEven = 0;
    int numOdd = 0;
    int [] evenNum;
    int [] oddNum;
    int [] ranNum = new int[25];


    for (i = 0; i <= 24; i++) {
        num = (int) (100 * Math.random());
        ranNum[i] = num;
        if (num % 2 == 0) {
            numEven += 1;
        } else numOdd += 1;
    }

    evenNum = new int[numEven];
    oddNum = new int [numOdd];

    for (i = 0; i <= 24; i++) {
        if (ranNum[i] % 2 == 0) {
            evenNum[countEven] = ranNum[i]; //This separates the two groups into different arrays. Is this a valid statement?
            countEven += 1;
        } else oddNum[countOdd] = ranNum[i];
        countOdd += 1;
    }

    System.out.print("Your even numbers are: \n");
    for (i = 0; i <= countEven; i++) {
        System.out.print(evenNum[i]);
    }

    System.out.print("Your odd numbers are: \n");
    for (i = 0; i <= countOdd; i++) {
        System.out.print(oddNum[i]);
    }



 }
}

Answer 1

countOdd += 1，尝试更改这些行：

} else oddNum[countOdd] = ranNum[i];
 countOdd += 1;

成：

} else { 
    oddNum[countOdd] = ranNum[i];
    countOdd += 1; 
}

更改（正如Lion建议的那样）

for (i = 0; i <= countEven; i++) {

和

for (i = 0; i <= countOdd; i++) {

到

for (i = 0; i < countEven; i++) {

和

for (i = 0; i < countOdd; i++) {

Answer 2

countOdd += 1;语句不在一对括号内，因此即使数字是偶数也会执行。

} else { 
    oddNum[countOdd] = ranNum[i];
    countOdd += 1; 
}

这可以解决您的错误。

Answer 3

oddNum数组长度为8 ...但是你使用了更大的countOdd，这会导致异常在线：

oddNum[countOdd] = ranNum[i];

导致此问题的原因是countOdd + = 1;不包含在括号内：

else addNum[countOdd++] = ranNum[i];

索引超出for语句的范围

3 个答案: