diffrent way Define a List of Objects in C#?

I have written a program that is supposed to get a list of names and information. Well, I got to solve this question a few classes, such as students and university have to answer. But the problem is where I plan to get students information

static void Main(string[] args) {

    Console.WriteLine("Some students enter the information you want? ");
    Cunt = int.Parse(Console.ReadLine());

    University university = new University();        
    university.Add();
    university.Sort();
    university.Report();
    Console.ReadKey();
}

To solve this problem, I have to specify the number of students .

class University { Student[] student = new Student[3]; 

 private int n = 0;
 public University()
 {

         for (int i = 0; i < 3; i++)
             student[i] = new Student();
 }

 public void Add()
 {
     Console.WriteLine();
     for (int i = 0; i < 3; i++)
     {
         student[n].Read();
         n++;
     }
 }

For example, the number of students I have three. How do I create a way to enter the number of students who give information and do not default؟Instead of the number 3 is a variable that give the user the desired number.

Then change the program with help from friends, but I got this problem.

class University
{
 //  Student[] student = new Student[3];
   public int NumbersOfStudents { get; private set; }

  public Student[] student;

   public University(int numberOfStudents)
    {
        for (int i = 0; i < numberOfStudents; i++)
            student[i] = new Student();
    }
     private int n = 0;
     /* public University()
      {

              for (int i = 0; i < 3; i++)
                  student[i] = new Student();
      }*/

But when I run it I get the error: Object reference not set to an instance of an object.

notic:The program can not I use the list.

Jon Skeet
people
quotationmark

You're never initializing your student field, so it's null. You could use:

// Note: public fields are almost *always* a bad idea
private readonly Student[] students;

public University(int numberOfStudents)
{
    students = new Student[numberOfStudents];
    for (int i = 0; i < numberOfStudents; i++)
    {
        students[i] = new Student();
    }
}

However, that's a pretty nasty solution, in my view - why are you creating all these useless Student objects? Why are you populating the University ahead of time?

It would be better to use List<T> rather than an array:

public class University
{
    private readonly IList<Student> students = new List<Student>();
    // Presumably some other fields and properties

    public void AddStudent(Student student)
    {
        students.Add(student);
    }
}

people

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