ruby is character
#Use a regular expression that matches letters & digits: def letter?(lookAhead) lookAhead.match?(/[[:alpha:]]/) end def numeric?(lookAhead) lookAhead.match?(/[[:digit:]]/) end #These are called POSIX bracket expressions, and the advantage of them is #that unicode characters under the given category will match. For example: 'ñ'.match?(/[A-Za-z]/) #=> false 'ñ'.match?(/\w/) #=> false 'ñ'.match?(/[[:alpha:]]/) #=> true #You can read more in Ruby’s docs for regular expressions. #https://ruby-doc.org/core/Regexp.html
