Palindrome checker in ruby

gistfile1.rb

class String
  def palindrome?
    is_p = true
    ch = self.gsub(/ /,"").chars.to_a
    
    compares = ch.length / 2
    back_index = ch.length - 1
    
    compares.times do |i|
      break unless is_p = (ch[i] == ch[back_index])
      back_index -= 1
    end
    
    is_p
  end
end

puts "rover".palindrome?  # false
puts "roger".palindrome?  # false 
puts "radar".palindrome?  # true
puts "madam im adam".palindrome? # true