From: Stefano Crocco <stefano.crocco@...>
Date: 2008-01-05T01:16:12+09:00
Subject: Re: iterating over array of variables - can't change them?

Alle venerd́ 4 gennaio 2008, AJS ha scritto:
> title="Title"
> subtitle="Subtitle"
> body="Body"
> [title,subtitle,body].each {|item| item.downcase!}
>
> This successfully sets the original variables to "title", "subtitle",
> "body"
>
> BUT
>
> [title,subtitle,body].each {|item| item=""}
>
> has no effect.
>
> Why doesn't this work? How can I make it work?
>
> thanks

The block variable (item) is set by ruby to "point to" each object of the 
array in turn. String#downcase! is a destructive method: it changes its 
receiver, so the elements of the original array get changed. On the other 
hand, when you do item = "", you're telling the variable itewm to "point to" 
another object, a new (empty) string. This doesn't modify the original array 
at all.

If you want to change the contents of the original array, your should use 
Array#map!:

[title,subtitle,body].map! {|item| ""}

Array#map! replaces each element of the array with the return value of the 
block.

I hope this helps

Stefano