Why and when should you use Xojo.Core.Dictionary rather than just class Dictionary?
Since that API is being deprecated (in favor of a “soon” to come API 2.0), you might not want to tie yourself to “xojo.core”
This is not new information, it has been discussed for some months on this forum already.
[and yes, deprecated does not mean removed… for now]
One reason would be if you are working on an iOS project which only uses the namespaced version.
I would say: Only on iOS.
For Mac/Win/Linux the usual dictionary is faster.
A Xojo.Core.Dictionary can be converted to JSON using Xojo.Data.GenerateJSON and be created from JSON using Xojo.Data.ParseJSON. This makes it very useful for working with Web Services.
FYI, you can do the same with the classic (soon to be API 2.0) framework with ParseJSON_MTC and GenerateJSON_MTC, found in my JSONItem_MTC project: