json.exams @exams.each do |exam|
  json.(exam, :id, :name, :difficulty, :quotes, :public)
  json.question_count exam.question_count
  json.total_score exam.total_score
  json.update_time exam.updated_at&.strftime("%Y-%m-%d %H:%M")
  json.apply exam.apply?
  json.author do
    json.login exam.user&.login
    json.name exam.user&.full_name
  end
end
json.exam_count @exams_count