## routes.rb

  devise_for :users
  root to: "home#index"
  match '/amount', to: 'amount#index',    via: 'get'
  match '/amount', to: 'amount#process', via: 'post'

## amount_controller.rb
  def index
    @user=current_user
  end
  def process
    case params[:type]
      when  "recharge"
      @user=current_user
      user.recharge(@user,params[:num])

      when  "transfer"
      @user=current_user
      user.recharge(@user,params[:num],params[:to])

    end

##这个时候请求'0000:3000/amount'会直接跑到process,然后蹦出一个这个错误

ArgumentError in AmountController#index
wrong number of arguments (1 for 0)

##然后改成 process(arg) 将arg 打出来是"index"

为什么？

谢谢。