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Contructor "good or bad"

Vxyz eom
Greenhorn

Joined: Aug 02, 2011
Posts: 4
Hello Folks !
I have a problem and doubts with constructors.
does any one tell me why constructor with parameters cannot be inherit ???remember the fact that default constructor can inherit.

this works well.
But Not Working Explain with Details ....!!!


-- Vinay [The Excavator of Mind]
vibhor sharma
Greenhorn

Joined: Dec 10, 2010
Posts: 19

I doubt even first one works well ..


It is not a constructor , eventually a valid java method which happens to be a same name as a class name .... remember constructors doesn't have return type, not even void .

PS : In my opinion constructors cant be inherited , be it default one ...
Matthew Brown
Bartender

Joined: Apr 06, 2010
Posts: 4465
    
    8

Here's what's going on...

You aren't specifying a constructor for the B class. So the compiler inserts a default constructor, taking no arguments.

Because B is a subclass of A, any constructor of B must call a constructor of A. Again, if you omit this, the compiler will insert the call for you. But it can only insert a no-arg constructor like this. In the second case, there isn't a no-arg constructor. So if you want to inherit from B in that case you need to put in the constructor calls explicitly. For instance, like this:



Actually, writing that I've realised there were two problems. Your examples didn't have any constructors. They were ordinary methods - constructors don't have a return type.

Vxyz eom
Greenhorn

Joined: Aug 02, 2011
Posts: 4
vibhor sharma wrote:I doubt even first one works well ..


It is not a constructor , eventually a valid java method which happens to be a same name as a class name .... remember constructors doesn't have return type, not even void .

PS : In my opinion constructors cant be inherited , be it default one ...

Now is it correct Vibhor ???
Vxyz eom
Greenhorn

Joined: Aug 02, 2011
Posts: 4
Matthew Brown wrote:Here's what's going on...

You aren't specifying a constructor for the B class. So the compiler inserts a default constructor, taking no arguments.

Because B is a subclass of A, any constructor of B must call a constructor of A. Again, if you omit this, the compiler will insert the call for you. But it can only insert a no-arg constructor like this. In the second case, there isn't a no-arg constructor. So if you want to inherit from B in that case you need to put in the constructor calls explicitly. For instance, like this:



Actually, writing that I've realised there were two problems. Your examples didn't have any constructors. They were ordinary methods - constructors don't have a return type.


Thanks Matthew You are Correct.
 
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subject: Contructor "good or bad"