From: David Kastrup <dak@...>
Date: 2006-11-20T06:25:05+09:00
Subject: Re: The last evaluated expression for this method?

Avi S g <avishek.sen.gupta@gmail.com> writes:

> I wrote a simple version of the collect method for the Array class 
> called my_collect. Here is what I wrote:
>
> class Array
>   def my_collect
>     result = []
>     self.each {|element| result.push(yield(element))}
>     result
>   end
> end
>
> x = [1,2,3].my_collect {|element| element + 1}
> print x
>
> It prints out 234 correctly. However, I was puzzled by what x contained 
> if I removed the return value 'result', that is:
>
> class Array
>   def my_collect
>     result = []
>     self.each {|element| result.push(yield(element))}
>     #Removed return value
>   end
> end
>
> x = [1,2,3].my_collect {|element| element + 1}
> print x
>
> It prints out 123. Why? The last evaluated expression would probably
> be result.push(yield(3)),

No.  The last evaluated block of self.each would be
result.push(yield(3)), but each does not return the last evaluated
block, but rather the original array.

> and since push returns the resulting array, wouldn't it be 234 in
> this case as well?

No.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum