specify ranges of characters inside the square brackets


# This scan matches all lowercase letters between a and m.

"This is a test".scan(/[a-m]/) { |x| puts x }

1.	extract numbers from a string
2.	uses \d to match any digit, and the + that follows \d makes \d match as many digits in a row as possible.
3.	scan through all the vowels in a string: [aeiou] means "match any of a, e, i, o, or u."
4.	Scan as split
5.	Splitting Sentences into Words
6.	scan a here document
7.	Scan for \w+
8.	Scan() string with hex value
9.	scan(/./u) string with hex value
10.	Count words for a string with quotation marks
11.	Just like /\w+/, but doesn't consider underscore part of a word.
12.	Anything that's not whitespace is a word.
13.	Accept dashes and apostrophes as parts of words.
14.	A pretty good heuristic for matching English words.

specify ranges of characters inside the square brackets : scan « String « Ruby