New to Ruby - how do I shuffle a string?

Question

Want to shuffle a string. This is my code: what is wrong about it? Thanks.

>> def string_shuffle(s)
>>   s.split('').shuffle(s.length()).join
>>   return s
>> end

Answer 1

If understand you correctly, you want this:

def string_shuffle(s)
  s.split("").shuffle.join
end

string_shuffle("The Ruby language")
=> "ea gu bgTayehRlnu"

Answer 2

return s is both not needed and wrong. Not needed because Ruby returns whatever is executed last and wrong because you are not changing s, you are creating a new string.

Furthermore, you can just add the shuffle method directly to String if you find it useful, but beware of monkeypatching too much.

class String

  def shuffle
    self.split('').shuffle.join
  end
end

Answer 3

This is faster. 'hello'.chars.shuffle.join

Test yourself:

require 'benchmark'

str = 'Hello' * 100
Benchmark.bm(10) do |x|
  x.report('chars')       { str.chars.shuffle.join }
  x.report('split')       { str.split('').shuffle.join }
  x.report('split regex') { str.split(//).shuffle.join }
end