是 double 和 Double 在 dart 中是不同的东西，如果是，谁能解释我

Question

as we can see this gives an error that is telling that 0.0 is double that can't assigned to Double datatype

then i tried Double as datatype and my code worked fine. but i don't understand what is going on here so can any one tell me what is going on here?

Answer 1

Double comes from dart ffi,

Represents a native 64 bit double in C. Double is not constructible in the Dart code and serves purely as marker in type signatures.

you mostly don't want it, use double instead.

Find more about numbers in dart and dart-ffi/Double