http://www.perlmonks.org?node_id=94375


in reply to Common Regex Gotchas

I'd like to point out that tr/a-z/A-Z/ does something different from uc or \U. The former won't deal with "Pea", for example. The latter treats accented characters correctly according to the language in use, and potentially handles weird things like German and letters in additon to the normal 26 in English, such as .