From: "David A. Black" <dblack@...>
Date: 2010-09-10T09:28:11+09:00
Subject: Re: How to do foo.chomp!.rstrip!.downcase!  ?

Hi --

On Fri, 10 Sep 2010, Geometric Patterns wrote:

>
> Rather than:
>
> foo.chomp!
> foo.rstrip!
> foo.downcase!
>
> ...it seems like I should be able to do:
>
> foo.chomp!.rstrip!.downcase!
>
> ...but I get: undefined method `downcase!' for nil:NilClass
> (NoMethodError)
>
> This is probably a basic ruby thing that I'm not grokking...

A lot of destructive ! methods return nil if the object isn't changed --
for example:

   "abc".gsub!(/z/, "y")
   => nil

So it's generally best not to chain them.


David

-- 
David A. Black, Senior Developer, Cyrus Innovation Inc.

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