convert_array_or_hash_to_csv.rb

def csv(data)
  arr = Array.wrap(data)
  CSV.open(csv_filename, 'wb') do |csv|
    keys = arr.first.keys
    # header_row
    csv << keys
    arr.each do |hash|
      csv << hash.values_at(*keys)
    end
  end
end

# Usage
# You can send either array or hash it should convert to CSV
# csv([{first_name: 'Ahmed', last_name: 'Ali'}, {first_name: 'Mohammed', last_name: 'majed'}])

# OR add this method in array class config/initializers/array.rb

class Array
  def to_csv(csv_filename='hash.csv')
    require 'csv'
    CSV.open(csv_filename, 'wb') do |csv|
      csv << first.keys
      self.each do |hash|
        csv << hash.values_at(*keys)
      end
    end
  end
end

# Usage
# [{first_name: 'Ahmed', last_name: 'Ali'}, {first_name: 'Mohammed', last_name: 'majed'}].to_csv('file_name.csv')