Why is return-type covariance enforced for hidden static methods?

Question

This code won\'t compile because of the String return type of the staticMethod in Child.

class Parent {
    static void st         


        

Answer 1

I see nothing wrong with how the compiler treated you, be your methods static or otherwise. Just the next couple of lines in the documentation say:

This rule allows for covariant return types - refining the return type of a method when overriding it. If R1 is not a subtype of R2, a compile-time unchecked warning occurs unless suppressed by the SuppressWarnings annotation (§9.6.3.5).

Clear. R1 must be a subtype of R2 like Integer is to another Integer or to Number. String is not subtype of void.

Documentation says: "compile-time unchecked warning occurs...". But what I noticed is that a full-fledged compilation error awaits.

Inheritance still works as expected. Remove your child method and you 'd have access to the parent's, static or otherwise.