Enthuware

" Since Eatable and Food both have a static int field name types"
is it true? Is field types in Eatable static?

Yes, all fields in an interface are public, static, and final. Even if you do not explicitly declare them so. This is OCA stuff
Paul.

The explanation makes sense, and when I alter the code in various ways things change as I would expect, though there is an interesting ramification: if the explicit “implements Eatable” declaration is removed from LINE 1 of Fruit the compile errors disappear. I assume this is because, although the class still inherits the Food ‘true’ and, indirectly, the Eatable ‘true’, the former shadows the latter. (Consistent with this, if LINE 2 is disabled/removed, Line 3 prints the ‘shadowing’ value, 20, and it can be confirmed that Fruit still implements Eatable indirectly through Food by showing that “new Fruit() instanceof Eatable” returns ‘true’.) So while I always assumed that ‘re-declaring’ an interface in a subclass of a class that implements that interface makes no difference, it seems it can affect ‘shadowing relationships’. (Another way to get LINE 2 and 3 to compile is to add an explicit declaration of a static ‘types’ field to Fruit in the original code, so that this third ‘types’ variable now shadows the others.)