Newbea question again?

Hello RoR Developers,

I have tiny problem about comparison. I have a array and hash. I want to
compare array elements with hash keys.
more details:
this is my hash, I create it from yaml file
my yaml file
template1:
  template_of_roster3: template_of_roster2
  template_of_roster4: template_of_roster3

@get_config=YAML.load(File.open("#{PATH_IM}/config/converter.yml"))
    @get_config == Hash
@my_hash==Hash
@enterprises=@get_config["template1"]

and my array
@my_array=["template_of_roster","template_of_roster2","template_of_roster3"]

my question here is that how can I compare array with hash keys and how
can I can send warning message to user?
@my_array.eql?(@@my_hash.key)==false
warn "warning message"

something like this.

thanks..