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Abstract Class and Inheritance

Hiep Nguyen
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Joined: Oct 26, 2001
Posts: 46
i write an abstract class that extends JFrame, and a subclass is extended the abstract class. but when i compile, it make an error at contructor. what should i do?
this is my code

thank you
Thomas Paul
mister krabs
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Joined: May 05, 2000
Posts: 13974
The normal reason for getting this error is, since the abstract class doesn't have a default constructor all the constructors of the extending class must have "super(title);" as the first staement in their constructors. The code snip you showed us should be fine.

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Michael Morris
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Joined: Jan 30, 2002
Posts: 3451
Hi Hiep,
You have a syntax error on your first ListForm class declaration: it should be abstract class instead of class abstract but that should not cause the error you say the compiler is indicating. By changing that, your code should compile. There must be some problem in the implementation of the abstract methods.
Hope this helps,
Michael Morris

Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius - and a lot of courage - to move in the opposite direction. - Ernst F. Schumacher
Hiep Nguyen
Ranch Hand

Joined: Oct 26, 2001
Posts: 46
thanh you for your replies !
in my working code, i passed wrong parameters, the misstake takes me long time to debug so i 'm really supid man
I agree. Here's the link:
subject: Abstract Class and Inheritance
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