Why is my interface's BaseType null?

Question

Interface definition

public interface IPayeePayrollRunInitialPayElementData : IPayeePayrollRunPayElementData

But in my code the BaseType of my interface is null. I cannot make any sense of this!

Answer 1

Because it's defined to be so?

Interfaces inherit from zero or more base interfaces; therefore, this property returns null if the Type object represents an interface. The base interfaces can be determined with GetInterfaces or FindInterfaces.

Answer 2

From Type.BaseType page;

Interfaces inherit from zero or more base interfaces; therefore, this property returns null if the Type object represents an interface. The base interfaces can be determined with GetInterfaces or FindInterfaces.

public interface IPayeePayrollRunInitialPayElementData : IPayeePayrollRunPayElementData
{ }

public interface IPayeePayrollRunPayElementData
{ }

class Program
{
    static void Main(string[] args)
    {
        foreach (Type tinterface in typeof(IPayeePayrollRunInitialPayElementData).GetInterfaces())
        {
            Console.WriteLine(tinterface.FullName);
        }
    }
}

Output will be;

IPayeePayrollRunPayElementData

Here is a DEMO.