将正确的分数排序为正确的名称（并行数组）C#

Question

如上所述，我正在尝试使用并行数组向正确的用户显示正确的分数，如果学生的分数低于 40，它应该显示学生的姓名和他们的分数。

目前我已经这样做了，但它没有将分数分配给正确的名称。

代码：

  static void Main(string[] args)
    {
        //bool YesNo = Console.ReadKey;
        // Empty Variable arrays declared for usage.
        int[] classScores = new int[5];
        string[] studentNames = new string[5];
        object[] ClassANDStudent = new object[5];

        //
        //   if (YesNo == true)
        //Loop Method for user input for student name.
        for (int i = 0; i < studentNames.Length; i++)
        {
            Console.WriteLine("Please enter a Student Name.");
            studentNames[i] = Console.ReadLine();

            Console.WriteLine("Please enter marks.");
            classScores[i] = Convert.ToInt32(Console.ReadLine());

        }
        //


        var Lessthan40Array = classScores.Where(OverallMark => OverallMark <= 40).ToArray();

        Array.Sort(studentNames, classScores, 0, studentNames.Length);
        Array.Sort(studentNames, Lessthan40Array, 0, Lessthan40Array.Length);

        for (int i = 0; i < studentNames.Length; i++)
        {
            ClassANDStudent[i] = studentNames[i] + " " + classScores[i];
        }



        //
       for (int i = 0; i < Lessthan40Array.Length; i++)
        {

            Console.WriteLine(studentNames[i] + " " + Lessthan40Array[i]);
          //  Console.WriteLine(" {0,-10}: {1}", studentNames[i], Lessthan40Array[i]);
        }

        Console.ReadKey();
    }

Answer 1

您真正需要做的就是遍历所有分数，并为分数小于 40 的任何索引输出学生信息（来自两个数组）。上面代码的问题是，一旦您排序数组之一，它们不再同步。

当我尝试从用户那里获取数字时，我通常做的第一件事就是创建一个辅助方法，该方法将进行一些验证（使用int.TryParse）以确保它们实际上输入了一个整数。此方法将字符串作为提示显示给用户，并一直提示他们，直到他们输入有效数字：

private static int GetIntFromUser(string prompt)
{
    int input;

    do
    {
        Console.Write(prompt);
    } while (!int.TryParse(Console.ReadLine(), out input));

    return input;
}

除此之外，下面的示例代码将提示用户输入他们想要输入的学生数量，然后将每个学生的姓名和分数收集到两个单独的数组中。然后它只是使用一个计数器循环遍历分数数组，并为任何得分低于 40 的人输出学生姓名和分数：

private static void Main()
{
    int numStudents = GetIntFromUser("Enter the number of students: ");

    int[] scores = new int[numStudents];
    string[] names = new string[numStudents];

    for (int i = 0; i < numStudents; i++)
    {
        Console.WriteLine("\nStudent #" + (i + 1));
        Console.Write(" - Enter student's name: ");
        names[i] = Console.ReadLine();
        scores[i] = GetIntFromUser(" - Enter student's score: ");
    }

    Console.WriteLine("\nHere are the students who scored less than 40:");

    for (int i = 0; i < numStudents; i++)
    {
        if (scores[i] < 40)
        {
            Console.WriteLine(" - " + names[i] + " scored " + scores[i]);
        }
    }

    GetKeyFromUser("\nDone! Press any key to exit...");
}

输出

Answer 2

如果你想在写分数之前实际排序：

static void Main(string[] args)
{
    int[] classScores = new int[]{30,50,25,39,62};
    string[] studentNames = new string[]{"Jim","John","Mary","Peter","Sarah"};
        Array.Sort(classScores, studentNames);   // sort both according to scores
    for (int i = 0; i < classScores.Length; i++)
    {
        if (classScores[i] < 40)
        {
            Console.WriteLine(classScores[i] + " " + studentNames[i]);
        }
    }
}

如果您有超过 2 个数组，请创建一个索引为 0 到 length-1 的数组：

static void Main(string[] args)
{
    int[] classScores = new int[]{30,50,25,39,62};
    string[] firstNames = new string[]{"Jim","John","Mary","Peter","Sarah"};
    string[] lastNames = new string[]{"Thorpe","Smith","Jones","Tork","Conner"};
    int[] index = new int[]{0,1,2,3,4};
        Array.Sort(classScores, index);   // sort both according to scores
    for (int i = 0; i < classScores.Length; i++)
    {
        if (classScores[i] < 40)
        {
            Console.WriteLine(classScores[i] + " " +
                firstNames[index[i]] + " " + lastNames[index[i]]);
        }
    }
}