Book says R file should be under app/build/generated/source/r/debug however, as of Android Studio version 3.3.1 the only folder under source is buildConfig. Where is the R file located now?
Did you ever figure this out? I’m stuck here now as well.
I found a possible fix, though it isn’t what the book says.
Build -> Clean Project
Build -> Rebuild Project
The path to the R.java file then should be in the directory
I really don’t know if this is the fix to this, I found it here: No R.Java (purchased book)
But even on that post someone implies that this shouldn’t be how our app is and there is possibly an error.
If and when I found a solution, I will let you know!
Have you tried a Clean and re-building the project? Android Studio used to do a preemptive build and it doesn’t seem to do that any longer. If you try this and still have an issue, let me know.