C# Understanding This IF Statement Logic

Question

Hi I have just used some code off a website for one of my classes in my C# project, I dont really understand all of the logic behind it as i am new to coding with C#. I was wondering if someone was able to write this code in pseudo and also explain the logic behind it.

 

string fullName = LastName;

if (!string.IsNullOrWhiteSpace(FirstName))

{

   if (!string.IsNullOrWhiteSpace(fullName))

   {

      fullName += ", ";

   }

   fullName += FirstName;

}

return fullName;

 

Thank you