ruby split string by repeating characters or a space

Question

How do i split this string.

"6885558 8866887777" => ["6", "88", "555", "8", "88", "66", "88", "7777"] 

I tried this, but it never worked.

ruby-1.8.7-p334 :020 > "111133".split(/(\d)\1+/)
 => ["", "1", "", "3"] 

Answer 1

split will just use whatever it matches as a delimiter, removing it from the string in question. What you're looking for is scan:

str = "6885558 8866887777"
str.scan(/((\d)\2*)/).map(&:first)
# => ["6", "88", "555", "8", "88", "66", "88", "7777"]

Taking it slow, the \d matches any digit. It's in the second capturing group, so \2* then matches any further occurrences of the same digit. This produces an array that looks like

[["6", "6"], ["88", "8"], ["555", "5"], ["8", "8"],
 ["88", "8"], ["66", "6"], ["88", "8"], ["7777", "7"]]

Since we only want the first item in each of those sub arrays, we can collect them all with map(&:first).

(Note that str.scan(/(\d)\1*/) would simply produce an array out of the first capturing group, which means we'd only get one digit from a sequence of possibly repeated numbers.)