palindrome.rb

class String
  # Opens up string class, to allow these methonds to be called directly on the string rather than passed as a variable to a method.
  def rev_string
    # Splits the string into an array, for iterative purposes
    str_arr = self.chars
    # Builds a temporary array
    tmp_arr = []
    str_arr.length.times do
      # grabs the end of the str_array, and makes it the first of our new array
      tmp_arr << str_arr.pop
    end
    # joins new array into strin
    return tmp_arr.join
  end

  def palindrome?
    # checks if proper length and if the first and last letters are equal, this keeps us from having to waste time reversing a string that wouldn't work as a palindrome
    if self.length < 2 || self[0] != self[-1]
      return false
    else
      # checks if a reversed string is equal to the unreversed string, method above
      self == self.rev_string
    end
  end
end

puts "'aa' is palindrome? #{"aa".palindrome?}"
puts "'ca' is palindrome? #{"ca".palindrome?}"
puts "'a' is palindrome? #{"a".palindrome?}"
puts "'racecar' is palindrome? #{"racecar".palindrome?}"
puts "'racecare is palindrome?' #{"racecare".palindrome?}"