Here’s a quote from p. 586 of one of our books:
Polymorphism is when a subclass “stands in” for its superclass.
10 points to everyone who can tell me what’s right about that statement as well as what’s wrong with it.
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Haven’t you gotten tired of that particular soapbox yet? :-)
(Polymorphism is when one class can stand in for any of an unbounded set of others, but it is not limited to inheritance.)
Right: Polymorphism is spelled correctly.
Wrong: The definition is for Inheritance.
the "stands in" description is OK, but a polymorphic function just needs to implement some interface, not be a subclass of an object?
Wrong: Polymorphism - when parrot changes into a parakeet.
Right: TMTOWTDI
What is wrong with it: an object instantiated from the subclass "stands in" -- not the sub class itself.
What is right with it: the subclass might override a virtual method.
Right: it's indeed on page 586.
Wrong: definitions do not go "a /thing/ is when ...". A thing is not when.
Whoops, I meant to respond to this ages ago. Aristotle, Michael, and joeblow are completely right. Ken is right in another way. mrgumby is correct to a degree, but polymorphism doesn't necessarily have anything to do with inheritance.
If it did, neither JavaScript nor Self would work.