列表的访问元素。 C＃

Question

I have created a List of type Students. The following classes are the ones I use;

public class StudentDetails
   {
   public class Address
    {
        public int HouseNumber{ get; set; }
        public string LineOne{ get; set; }
        public string LineTwo{ get; set; }
    }

    public class Student
    {
        public int StudentId { get; set; }
        public Address StudentAddress{ get; set; }
    }



    public List<Student> GetStudents()
    {
    private Address StudentOne = new Address{//details};
    private Address StudentTwo = new Address{//details};

    var students = new List<Student>();
    students.add(new Student {StudentId = 1, StudentAdress = StudentOne, //details});
    //more students
    return students;
    }

}

Now I would like to access certain details of a particular student from this object. Say I want to get the House number of a student. How can i do that? I attempted to create another list, then add the list returned from GetStudents() . However when i iterate through it , i only get references to objects.

//To access the List 

  StudentDetails student = new StudentDetails(); //create new instance
  for (int i = 0; i < student.GetStudents().Count; i++)
  {
            //Console.WriteLine(student[1].GetStudents());
  }

Answer 1

You can use Linq to select the student you are searching for and then access its properties:

var student = GetStudents().FirstOrDefault(student => student.StudentId /* your student id here */>);
if (student != null)
{
    var houseNumber = student.Address.HouseNumber;
}

Answer 2

Try this

StudentDetails student = new StudentDetails(); //create new instance
foreach (var s in student.GetStudents())
{
   var id = s.StudentId;//use any properties using . operator
   Console.WriteLine(s);
}

Answer 3

Console.WriteLine(GetStudents()[0].HouseNumber.ToString());

(0 can be whatever number)

or (gets a list of students and their house numbers) :

var houseNumbers = GetStudents().Select((student) => 
    String.Format("Student: {0} - {1}", 
    student.StudentId, student.Address.HouseNumber));
foreach(var entry in houseNumbers) Console.WriteLine(entry);