From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2010-01-28T00:43:07+09:00
Subject: Re: Class with Multi Constrcutor ( initialize )

On Wed, Jan 27, 2010 at 4:34 PM, Mido Peace <mido.peace@gmail.com> wrote:
> Hey ..
> I'm Tryin' to port Some Java Module into Ruby , but I have a small
> probleme ,
> how can I do to declare multi 'initialize Method' depending of the
> number of user
> argument
>
> i.e in Java we can have a Class with many constructor
> class myClass {
>
>   //...
>    public MyClass () { ... }  // Defualt One
>    public MyClass (Object obj1 ) { ... }
>    public myClass  ( Object obj1,Object obj2 ...,Object objn) { ... }
>  // ...
> }
>
> I tried :
> class myClass
>   def initialize ()
>     // ...
>   end
>
>   def intialize ( value )
>    // ...
>   end
> end
>
> but doesnt works !
>
> I just wanna find a way to call the right constructor ( or initializer)
> depending of the number of arguments

Ruby doesn't support method overloading. If you need different
implementations just depending on the number of arguments you can do:

class MyClass
   def initialize *args
      case args.size
      when 1
          _init_1_param *args
      when 2
          _init_2_params *args
      ....
   end
end

or you can do this:

class MyClass
   def initialize(options = {})
   # and have the logic depend on the keys present in the hash
   end
end

So you can call:

MyClass.new
MyClass.new(:obj1 => some_object, :obj2 => some_other_object)

Hope this helps,

Jesus.