Reverse a string in Ruby

Question

How do you reverse a string in Ruby? I know about string#reverse. I\'m interested in understanding how to write it in pure Ruby, preferably an in-place solution.

Answer 1

Here's an alternative using the xor bitwise operations:

class String

  def xor_reverse
    len = self.length - 1
    count = 0

    while (count < len)
      self[count] ^= self[len]
      self[len] ^= self[count]
      self[count] ^= self[len]

      count += 1
      len -= 1
    end

  self
end

"foobar".xor_reverse
=> raboof