Initialize and superclass

Hi
I'd like to know something :
Lets say I have two classes A and B, where A is B's superclass. B's
initialize method initialize her own variables, but how could I do in
order to run A.initialize before B.initialize when I write B.new ?
I hope my text is understandable.
Thanks everyone.
Bye

Julien Vivenot

jvivenot [2006-08-21 01:35]:

Lets say I have two classes A and B, where A is B's superclass. B's
initialize method initialize her own variables, but how could I do in
order to run A.initialize before B.initialize when I write B.new ?

If I understood your problem correctly, you're after the "super" method.
Try the following code:

class A
  def initialize
    puts "initializing instance of A"
  end
end

class B
  def initialize
    super
    puts "initializing instance of B"
  end
end

Regards,
Tilman

···

--
A: Because it messes up the order in which people normally read text.
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A: Top-posting.
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Tilman Sauerbeck wrote:

jvivenot [2006-08-21 01:35]:

Lets say I have two classes A and B, where A is B's superclass. B's
initialize method initialize her own variables, but how could I do in
order to run A.initialize before B.initialize when I write B.new ?

If I understood your problem correctly, you're after the "super" method.
Try the following code:

<snip />

And in the event that you some arguments to B that
A does not know how to handle, use the second form:

class A
   def initialize(foo)
     puts "initializing instance of A with #{foo}"
   end
end

class B
   def initialize(foo, bar)
     super(foo)
     puts "initializing instance of B with #{foo} and #{bar}"
   end
end

···

Regards,
Tilman

--
Posted via http://www.ruby-forum.com/.

Wonderful !
Thanks.

I think there will be many days during which I'll stay a Ruby-Nuby....

Bye, and thanks everyone

Julien Vivenot

Eero Saynatkari wrote:

···

Tilman Sauerbeck wrote:
> jvivenot [2006-08-21 01:35]:
>> Lets say I have two classes A and B, where A is B's superclass. B's
>> initialize method initialize her own variables, but how could I do in
>> order to run A.initialize before B.initialize when I write B.new ?
>
> If I understood your problem correctly, you're after the "super" method.
> Try the following code:
>
> <snip />

And in the event that you some arguments to B that
A does not know how to handle, use the second form:

class A
   def initialize(foo)
     puts "initializing instance of A with #{foo}"
   end
end

class B
   def initialize(foo, bar)
     super(foo)
     puts "initializing instance of B with #{foo} and #{bar}"
   end
end

> Regards,
> Tilman

--
Posted via http://www.ruby-forum.com/.

Actually, it seems that I if I write only super because the super
initialize needs no argument, the super method gives every arguments of
the B class to the A initialize, and thus I encounter a ArgumentError.
That's OK
Thanks

Julien Vivenot

jvivenot wrote:

···

Wonderful !
Thanks.

I think there will be many days during which I'll stay a Ruby-Nuby....

Bye, and thanks everyone

Julien Vivenot

Eero Saynatkari wrote:
> Tilman Sauerbeck wrote:
> > jvivenot [2006-08-21 01:35]:
> >> Lets say I have two classes A and B, where A is B's superclass. B's
> >> initialize method initialize her own variables, but how could I do in
> >> order to run A.initialize before B.initialize when I write B.new ?
> >
> > If I understood your problem correctly, you're after the "super" method.
> > Try the following code:
> >
> > <snip />
>
> And in the event that you some arguments to B that
> A does not know how to handle, use the second form:
>
> class A
> def initialize(foo)
> puts "initializing instance of A with #{foo}"
> end
> end
>
> class B
> def initialize(foo, bar)
> super(foo)
> puts "initializing instance of B with #{foo} and #{bar}"
> end
> end
>
> > Regards,
> > Tilman
>
> --
> Posted via http://www.ruby-forum.com/.

If you don't want to pass any arguments to the superclass's initialize
use this version:

  super() # no arguments

So you've got:

  super # pass along the arguments to the current method
  super() # pass no arguments
  super(1,2) # pass these explicit arguments

Gary Wright

···

On Aug 20, 2006, at 6:25 PM, jvivenot wrote:

Actually, it seems that I if I write only super because the super
initialize needs no argument, the super method gives every arguments of
the B class to the A initialize, and thus I encounter a ArgumentError.
That's OK
Thanks

Oh, thanks, but actually, I found it by myself, my previous message was
a just a notification of the fact that it would be better to write ()
instead of nothing just after super.
Thanks anyway.
Bye

Julien Vivenot

gwtmp01@mac.com wrote:

···

On Aug 20, 2006, at 6:25 PM, jvivenot wrote:

> Actually, it seems that I if I write only super because the super
> initialize needs no argument, the super method gives every
> arguments of
> the B class to the A initialize, and thus I encounter a ArgumentError.
> That's OK
> Thanks

If you don't want to pass any arguments to the superclass's initialize
use this version:

  super() # no arguments

So you've got:

  super # pass along the arguments to the current method
  super() # pass no arguments
  super(1,2) # pass these explicit arguments

Gary Wright