formulas.dart

dynamic _formulas = {
     '0':[1,0.001,0,0,3.28084,0.000621371,0,0],
     '1':[1000,1,0,0,3280.84,0.621371,0,0],
     '2':[0,0,1,0.0001,0,0,0.00220462,0.035274],
     '3':[0,0,1000,1,0,0,2.20462,35.274],
     '4':[0.3048,0.0003048,0,0,1,0.000189394,0,0],
     '5':[1609.34, 1.60934,0,0,5280,1,0,0],
     '6':[0,0,453.592,0.453592,0,0,1,16],
     '7':[0,0,28.3495,0.0283495,3.28084,0,0.0625, 1],
     };
 }

Q/ What is the type of this variable?
is it the same as Map<String, List> or another thing?

Yes, It is a Map<String, List> as you said.

A visit from the book Flutter Proyects 👍

I don't quite understand the reason why the author chose to represent this data this way, whereas a List<List<double>> is much more direct, and doesn't force us to perform a temporary conversion to (and from) string in the method.
I suppose the intent was to make the code more explicit and easy to read, but it's kind of clumsy.

Thank you. Great Work!!

wow