What is the best way to chop a string into chunks of a given length in Ruby?

Question

I have been looking for an elegant and efficient way to chunk a string into substrings of a given length in Ruby.

So far, the best I could come up with is this:

Answer 1

test.split(/(...)/).reject {|v| v.empty?}

The reject is necessary because it otherwise includes the blank space between sets. My regex-fu isn't quite up to seeing how to fix that right off the top of my head.

Answer 2

Here is another way to do it:

"abcdefghijklmnopqrstuvwxyz".chars.to_a.each_slice(3).to_a.map {|s| s.to_s }

=> ["abc", "def", "ghi", "jkl", "mno", "pqr", "stu", "vwx", "yz"]

Answer 3

I think this is the most efficient solution if you know your string is a multiple of chunk size

def chunk(string, size)
    (string.length / size).times.collect { |i| string[i * size, size] }
end

and for parts

def parts(string, count)
    size = string.length / count
    count.times.collect { |i| string[i * size, size] }
end