java-重复的号码检查并不总是有效

我有一个函数getNormalList(),该函数必须返回带有3个随机整数0-5的列表,但并不完全相同.它没有像我希望的那样工作.有时,尽管进行了检查,但仍输出相同的3个数字.

public class SpinResultGenerator {

    public ArrayList<Integer> getNormalList() {
        ArrayList<Integer> integerList = new ArrayList<Integer>();
        Random r = new Random();
        int Low = 0;
        int High = 6;
        for (int i = 0; i < 3; i++) {
            int number = r.nextInt(High - Low) + Low;
            integerList.add(number);
        }
        if (integerList.get(0) == integerList.get(1) && integerList.get(0) == integerList.get(2)
                && integerList.get(1) == integerList.get(2)) {
            integerList.clear();
            for (int i = 0; i < 3; i++) {
                int number = r.nextInt(High - Low) + Low;
                integerList.add(number);
            }
        }
        return integerList;
    }

    public ArrayList<Integer> getJackpotList() {
        ArrayList<Integer> integerList = new ArrayList<Integer>();
        integerList.add(5);
        integerList.add(5);
        integerList.add(5);
        return integerList;
    }
}

例如,如果结果为[4,4,4],则for循环将生成新数字.但是它仍然能够输出3个相同的整数.为什么？

解决方法:

您需要一个嵌套循环.您的for循环应重复进行,直到找到3个可接受的数字为止.我使用数组使代码更紧凑,但是使用ArrayList也可以做到这一点.

public List<Integer> getNormalList() {
    Random r = new Random();
    int[] arr = new int[3]; // initialized to 0s by default
    int Low = 0;
    int High = 6;
    while (arr[0] == arr[1] && arr[1] == arr[2]) { // will repeat as long as the 3 number as
                                                   // all equal
        for (int i = 0; i < arr.length; i++) {
            arr[i] = r.nextInt(High - Low) + Low;
        }
    }
    return Arrays.asList(arr);
}

标签：if-statement,for-loop,random,java
来源： https://codeday.me/bug/20191109/2010670.html