From: Daniel Schierbeck <daniel.schierbeck@...>
Date: 2006-07-25T20:10:08+09:00
Subject: Re: Defining a method with an argument with a default value

Pedro C�rte-Real wrote:
> I have this line in a class method to define an initializer:
> 
> define_method(:initialize){|value| @value = value}
> 
> But I want something more like this:
> 
> define_method(:initialize){|value=nil| @value = value if value}

First of all, you don't need the `if value' part -- when Ruby sees 
@value, it is immediately created, with the value nil, so there's no 
problem with giving it the value nil explicitly. Second, I believe you 
can just do this:

   define_method(:initialize){|value| @value = value}

If #initialize is called with no arguments, `value' will just be nil, 
although IRB may issue a warning.


Cheers,
Daniel