def index
      @parameters = Parameter.all
  
      respond_to do |format|
        format.html # index.html.erb
        format.json { render json: @parameters }
      end
    end
def index
      @parameters = Parameter.all
  
      respond_to do |format|
        format.html # index.html.erb
        format.json { render json: @parameters }
      end
    end
GET /parameters
 GET /parameters.json