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C# Entity Framework Basics Extending Our Entity Data Model Defining a Many-to-Many Relationship

Posted by Chris Robles
Chris Robles
23,611 Points

Defining A Many to Many Relationship Task 2

I don't understand what I'm doing wrong here. I'm getting the following error:

Course.cs(7,18): error CS1520: Class, struct, or interface method must have a return type Student.cs(7,16): error CS1520: Class, struct, or interface method must have a return type Compilation failed: 2 error(s), 0 warnings

Isn't not having a return type a defining characteristic of the constructor?

Course.cs 
using System.Collections.Generic;

namespace Treehouse.CodeChallenges
{
    public class Course
    {
          public Courses()
        {
            Students = new List<Student>();   
        }

        public int Id { get; set; }
        public int TeacherId { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        public int Length { get; set; }

        public ICollection<Student> Students { get; set; }

        public Teacher Teacher { get; set; }
    }
}
Student.cs 
using System.Collections.Generic;

namespace Treehouse.CodeChallenges
{
    public class Student
    {
        public Course()
        {
               Courses = new List<Course>();
        }

        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }

        public ICollection<Course> Courses { get; set; }
    }
}

1 Answer

Fredrik Rönnehag
Fredrik Rönnehag
2,342 Points
Fredrik Rönnehag
Fredrik Rönnehag
2,342 Points

In your default construction you didn't use the same name as the class. Therefor the compiler thinks you are creating a new method but you have no return type (example, void).

This code should fix the problem. Remember that constructors are a way of calling the class. Having no input parameters means it will be the default call when you call that class.

          public Course()
        {
            Students = new List<Student>();   
        }

          public Student()
        {
            Courses = new List<Course>();   
        }