Learn Java Programming - Instanceof Operator Tutorial

The first thing that we need to understand is the definition of a supertype. A supertype is a class or interface that is higher up the inheritance hierarchy. The instanceof operator compares an object(instance) to the Name of a supertype and returns a boolean result. The instanceof operator will also return true if the instance is of the same class name.
(reference variable) instanceof (Name of supertype)
String s = "Hello World";
s instanceof Object; // true

[nickwoodward]

But aren't you calling variations on a theme - showContent()? so polymorphic calls are an appropriate replacement for instanceof.

But what if you wanted to do something completely different with a CerealBox - for example throw it away? You wouldn't implement that in an overridden showContent() method would you?