reverse_string

reverse_string.rb

def reverse_str(str)
  str.split('').tap do |str_ary|
    len = str_ary.length
    (0..len / 2).each do
      left = i
      right = len - i - 1
      str_ary[left], str_ary[right] = str_ary[right], str_ary[left]
    end
    str_ary.reduce(:+)
  end
end