ONAMWAM - Overriding a Non-Abstract Method With an Abstract Method

Checks for the overriding of non-abstract methods by abstract methods in a subclass.

Wrong

class Animal {
    void func () {}
}
abstract class Elephant extends Animal {
    abstract void func ();
}

Tip: If it is a coincidence of names, rename your method. Otherwise, make this method abstract in an ancestor class or non-abstract in descendant.

Right

class Animal {
    void func () {}
}
abstract class Elephant extends Animal {
    abstract void extFunc ();
}