删除选择题

app/controllers/challenges_controller.rb

@@ -234,7 +234,7 @@ class ChallengesController < ApplicationController
   #   {...}, ...]
   #}
   def crud_answer
-    if @challenge.challenge_answers && params[:challenge_answer].empty?
+    if @challenge.challenge_answers && params[:challenge_answer].blank?
       @challenge.challenge_answers.destroy_all
     else
       raise '参考答案不能为空' if params[:challenge_answer].empty?