Introduction to OOP

Chapter 16: Overriding :

Chapter Summary

An override occurs when a method in the child classes uses the same name and type signature as a method in the parent class.
Unlike overloading, overriding is resolved at run-time.
There are two possible means for an overriding, replacement and refinement.
A name can shadow another name. Some languages permit both shadowing and overriding. Shadowing is resolved at compile time.
A change in the type signature can be covariant or contravariant, if it moves down or up the type hierarchy. The semantics of both types of change can be subtle.