From: "Y. NOBUOKA" <nobuoka@...>
Date: 2011-01-24T19:30:32+09:00
Subject: Re: How to convert letters to uppercase?

Hi, Richard

When the string doesn't contain a period, you want to change all
letters to uppercase? or not?
If you want to do, the following code is not good for you:

> str.sub!(/\A.*?\./) { $&.upcase }

str = "hello"
str.sub!(/\A.*?\./) { $&.upcase }
puts str
  # hello

Please use the following regexp instead:

str.sub!( /\A[^\.]*/ ) { |s| s.upcase }

str = "hello"
str.sub!( /\A[^\.]*/ ) { |s| s.upcase }
puts str
  # HELLO

Regards,
-- 
信岡 ゆう (NOBUOKA Yu)