Question

我正在使用C＃控制台应用程序开展足球联赛项目。我试图从阵列中选择随机球队，其中包含在主场和客场比赛的球队。当我试图生成9个随机数时，只生成8个数而0不生成，所以代码不能打破for循环。我想问题是if语句不允许生成相同的数字和int数组元素＆＃39;默认值为0.

这是代码和输出：

C# Code Output

    int randomHome; //Random number genetator for choosing a random iteration value from home array which containss the teams which plays at their home
    int randomAway; //Random number genetator for choosing a random iteration value from awayarray which containss the teams which plays at away

      Random randomNum = new Random();

      int[] randomHomeNumArray = new int[home.Length]; //array will hold the randomHome values and home array is the array which is holding the team's iteration values which plays at their home
      int[] randomAwayNumArray = new int[away.Length]; //array will hold the randomAway values and away array is the array which is holding the team's iteration values which plays at away
         for (int homeArrayCounter = 0; homeArrayCounter < randomHomeNumArray.Length; homeArrayCounter++)
        {
            randomHome = randomNum.Next(home.Length)

            if (!randomHomeNumArray.Contains(randomHome) )
            {
                randomHomeNumArray[homeArrayCounter] = randomHome;   //It will hold the randomHome values
                Console.WriteLine(homeArrayCounter + ". iterasyon in Home " + randomHomeNumArray[homeArrayCounter]);
            }
            else
            {
                homeArrayCounter--;
            }
        }
        Console.WriteLine("\n\n");


        for (int awayArrayCounter = 0; awayArrayCounter < randomAwayNumArray.Length; awayArrayCounter++)
        {
            randomAway = randomNum.Next(randomAwayNumArray.Length);    

            if (!randomAwayNumArray.Contains(randomAway))
            {
                randomAwayNumArray[awayArrayCounter] = randomAway;     //It holds the random valures from away array which contains the teams which plays at away
                Console.WriteLine(awayArrayCounter + ". iterasyon in Away " + randomAwayNumArray[awayArrayCounter]);
            }

            else
            {
                awayArrayCounter--;
            }
        }

Answer 1

当您初始化数组时，默认情况下每个索引的值为0。当您使用随机数时，它总是跳过0，因为它已经存在。

您可以尝试这样： -

for(int i= 0; i<randomHomeNumArray.Length; i++){
            randomHomeNumArray[i] = -1;
        }

        for (int homeArrayCounter = 0; homeArrayCounter < randomHomeNumArray.Length; homeArrayCounter++)
        {
            do{
                randomHome = randomNum.Next(home.Length);
            } while(!randomHomeNumArray.Contains(randomHome));
            randomHomeNumArray[homeArrayCounter] = randomHome;   //It will hold the randomHome values
            Console.WriteLine(homeArrayCounter + ". iterasyon in Home " + randomHomeNumArray[homeArrayCounter]);
        }

Answer 2

您似乎正在尝试随机化数组。

请改为尝试：

Random randomNum = new Random();

int[] randomHomeNumArray = Enumerable.Range(0, home.Length).OrderBy(_ => randomNum.Next()).ToArray();
int[] randomAwayNumArray = Enumerable.Range(0, away.Length).OrderBy(_ => randomNum.Next()).ToArray();

那就是它。完成。

Answer 3

您的问题是数组的默认初始化：

int[] randomHomeNumArray = new int[home.Length];

这会创建一个充满0的数组，因为0是int的默认值。

那么你的if条件

if (!randomHomeNumArray.Contains(randomHome))

对于false，

始终为0，因为0已包含在数组中。

您可以像这样初始化数组：

int[] randomHomeNumArray = Enumerable.Repeat(-1, home.Length).ToArray();

因此，请使用-1代替0，而if条件有效。

Answer 4

由于int不是无法使用的数据类型，因此默认情况下会使用零初始化int[]。所以即使你认为它是一个空数组，它实际上是一个所有元素都设置为零的数组。

要解决此问题，您可以考虑使用int?[]（null-able int数组）。或者，您可以使用负整数或大于最大包含上限的某个整数初始化数组。更好的是，以更好的方式实现您想要的，使用 @Enigmativity 提供的解决方案，并标记他的答案，如果有帮助的话。

C＃随机数不生成0

4 个答案: