From: Sebastian Hungerecker <sepp2k@...>
Date: 2008-01-05T01:23:06+09:00
Subject: Re: iterating over array of variables - can't change them?

AJS wrote:
> title="Title"
> subtitle="Subtitle"
> body="Body"
> [title,subtitle,body].each {|item| item.downcase!}
>
> This successfully sets the original variables to "title", "subtitle",
> "body"

No, it doesn't. It changes the strings, it doesn't do anything to the 
variables. The variables still point to the same object as before, it's
just the objects that are different now.


> [title,subtitle,body].each {|item| item=""}
>
> has no effect.
>
> Why doesn't this work? How can I make it work?

It works just fine. It just doesn't do what you want it to. Here's what it 
does:
It takes each of the elements in the array and then yields it. The code in the 
block will then run with item pointing to the element. After the assignment 
(item="") item will point to an empty string. This has no effect whatsoever 
on the variables title, subtitle and body.
What you want is map instead of each (which gives you a new array containing 
the results of yielding each item) or String#replace instead of reassignment 
(which would change the object instead of the variable).


HTH,
Sebastian
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