No matter how I understand the implementation of the calculated field

Question

Microsoft

Hello,
Oddly stupid question, but I don't understand the implementation of a calculated field in visual studio... , namely in a foreach loop
Can someone explain to me on skype?
I will be very grateful.

Answer 1

All figured out.
There, in principle, everything is written correctly, but neither in the video nor in the documentation does it say where the Order_Detail value comes from

Answer 2

There is an error in the c# code. option on VB - correct, imho. Open it and understand what the author meant.