From: Robert Klemme <bob.news@...>
Date: 2004-10-06T18:19:55+09:00
Subject: Re: Upcase array


"Thomas Leitner" <t_leitner@gmx.at> schrieb im Newsbeitrag
news:20041006111500.3dd9454c@localhost...
> On Wed, 6 Oct 2004 17:41:50 +0900
> Fredrik Jagenheim <jagenheim@gmail.com> wrote:
>
> | Given this array:
> | foo = %w { FOO BAR baz biz }
> |
> | How do I make all the entries uppercase in a short and readable way?
> |
> | The (to me) obvious solution won't work:
> | foo.map! { |x| x.upcase! }
> | as upcase returns nil if it doesn't have anything to upcase...
> |
> | //F
> |
> |
>
> Do not use x.upcase! but x.upcase (without the exclamation mark):
>
> irb(main):005:0> foo = %w{ FOO BAR baz biz }
> => ["FOO", "BAR", "baz", "biz"]
> irb(main):006:0> foo.map! { |x| x.upcase }
> => ["FOO", "BAR", "BAZ", "BIZ"]

Even more efficient is the usage of #each and #upcase!

>> foo = %w{ FOO BAR baz biz }
=> ["FOO", "BAR", "baz", "biz"]
>> foo.each {|s| s.upcase!}
=> ["FOO", "BAR", "BAZ", "BIZ"]
>>

Here, no new instances are created.

Regards

    robert