How can I check a word is already all uppercase?

Question

I want to be able to check if a word is already all uppercase. And it might also include numbers.

Example:

GO234 => yes
Go234 => no
         


        

Answer 1

You could either compare the string and string.upcase for equality (as shown by JCorc..)

irb(main):007:0> str = "Go234"
=> "Go234"
irb(main):008:0> str == str.upcase
=> false

OR

you could call arg.upcase! and check for nil. (But this will modify the original argument, so you may have to create a copy)

irb(main):001:0> "GO234".upcase!
=> nil
irb(main):002:0> "Go234".upcase!
=> "GO234"

Update: If you want this to work for unicode.. (multi-byte), then string#upcase won't work, you'd need the unicode-util gem mentioned in this SO question