From: Jari Williamsson <jari.williamsson@...>
Date: 2008-02-08T18:45:29+09:00
Subject: Re: info on block arguments

Russell Me wrote:

> 3.times {|x| puts x }
> 
> the output is 0,1,2 because... x is initially nil and a value of 1 is 
> returned (by... what?) to .times? is that right?

Perhaps the easiest way is to explain with a method that basically does 
the same thing as times:

---
class Fixnum
   def my_times
      return if !block_given?
      i = 0
      while (i < self)
        yield(i)
        i += 1
      end
   end
end

3.my_times {|x| puts x }
---

* The line "return if !block_given?" is used to prevent crash if the 
method is called without code block.

* In the case of Fixnum above, "self" is the same as the digit

* The code block is called by "yield(i)", but the value of i will be 
named x in your code block.


Best regards,

Jari Williamsson