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abstract class

eswar kumar
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Joined: Oct 20, 2002
Posts: 98
what is the use of constructor in a abstract class
Michael Morris
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Joined: Jan 30, 2002
Posts: 3451
All classes must have, at a minimum, a default (parameterless) constructor, even classes which cannot be instantiated. A constructor for an abstract class is no different than one for a concrete class. You do any necessary initialization and configuration in an abstract class' constructor just like you do in any other constructor.

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Tony Morris
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Joined: Sep 24, 2003
Posts: 1608
A constructor of an abstract class might enforce the need for parameter(s) at instantiation time.
The following example doesn't demonstrate the reasons for having such an enforcement, as this would require a real world scenario, perhaps you can provide an analogy for yourself.
abstract class A
// Enforce the need for a String argument for instantiation.
A(String s){/*blah*/}
class B extends A
// Remove the following line and super() is assumed which won't compile
// because there is no super default constructor.

Tony Morris
Java Q&A (FAQ, Trivia)
I agree. Here's the link:
subject: abstract class
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