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Extendable, but not instantiatable
David Duran
Ranch Hand
Joined: Feb 11, 2002
Posts: 122
I want to make a class extendable, but not instantiatable. Is that even possible?
Bear Bibeault
Author and ninkuma
Marshal
Joined: Jan 10, 2002
Posts: 56554
Declare it abstract, or give it a private constructor. hth, bear
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David Duran
Ranch Hand
Joined: Feb 11, 2002
Posts: 122
Thanks Bear. I'll try the abstract idea, but the private constructor idea can't work. If a subclass extends a superclass, the superclass' constructorwill be called before the subclass'. If the superclass' constructor is private, it will through a compile-time error.
Thomas Paul
mister krabs
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Joined: May 05, 2000
Posts: 13974
posted Feb 11, 2003 09:02:00
0
One of the key purposes of making a class abstract is to prevent it from being instantiated. Abstract classes do not have to have abstract methods.
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subject: Extendable, but not instantiatable