From efd83e4f81db45815cb373e967b2434a8512fe44 Mon Sep 17 00:00:00 2001
From: cxt <853663049@qq.com>
Date: Thu, 18 Jul 2019 17:12:19 +0800
Subject: [PATCH] =?UTF-8?q?=E8=B0=83=E6=95=B4?=
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---
 app/helpers/exercises_helper.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/helpers/exercises_helper.rb b/app/helpers/exercises_helper.rb
index 6f30ba6c3..ace9e062e 100644
--- a/app/helpers/exercises_helper.rb
+++ b/app/helpers/exercises_helper.rb
@@ -118,7 +118,7 @@ module ExercisesHelper
         if ex.question_type == Exercise::MULTIPLE  #多选题
           right_user_ids = user_ids
           standard_answer.each do |choice_position|
-            standard_answer_choice_id = ex_choices.select{|ec| ec.choice_position == choice_position}.first.id
+            standard_answer_choice_id = ex_choices.select{|ec| ec.choice_position == choice_position}.first&.id
             right_user_ids = right_user_ids & effictive_users.select{|answer| answer.exercise_choice_id == standard_answer_choice_id}.pluck(:user_id)
           end
           right_users_count = right_user_ids.size
@@ -130,7 +130,7 @@ module ExercisesHelper
           #   end
           # end
         else  #单选题和判断题
-          standard_answer_choice_id = ex_choices.select{|ec| ec.choice_position == standard_answer.first}.first.id
+          standard_answer_choice_id = ex_choices.select{|ec| ec.choice_position == standard_answer.first}.first&.id
           right_users_count = effictive_users.select{|answer| answer.exercise_choice_id == standard_answer_choice_id}.size
         end