match key of hash and then fetch values accordingly in ruby -

i have included given code:

@classes = {1=>"usa", 3=>"france", 2=>"uk",  5=>"europe", 7=>"delhi", 8=>"test"} @amaze = params[:test]  #i "1,3,7" 

i this, please guide me how match keys @amaze , accordingly fetch values @classes i.e usa, france, delhi.

since @amaze string, lets first convert in array easy enumerate:

@amaze = "1,3,7" @amaze = @amaze.split(",") # => ["1", "3", "7"] 

now, since have keys extract values:

@amaze.map { |i| @classes[i.to_i] } # => ["usa", "france", "delhi"]