如何用更少的行写这个条件？

Question

我在模型中编写了以下代码：

percentage = 0
if self.date_of_birth.present?
  percentage += 15
end
if self.gender.present?
  percentage += 15
end
if self.relationship_status.present?
  percentage += 10
end
if self.language.present?
  percentage += 10
end
if self.qualification.present?
  percentage += 10
end
if self.interests.present?
  if self.interests.count >= 10
    percentage += 10
  else
    percentage += self.interests.count * 5
  end
end

但这看起来并不好。 小事情很多。 我想减少行数。

Answer 1

您可以内联，如下所示：

percentage += 15 if self.date_of_birth.present?

代替这个：

if self.interests.count >= 10
    percentage += 10
else
    percentage += self.interests.count*5
end

您可以使用三元运算符：

percentage += self.interests.count >= 10 ? 10 : self.interests.count*5

Answer 2

percentage = [
  (15 if date_of_birth.present?),
  (15 if gender.present?),
  (10 if relationship_status.present?),
  (10 if language.present?),
  (10 if qualification.present?),
  ((counts = interests.count.to_i) >= 10 ? 10 : (counts * 5)),
].compact.sum

Answer 3

您可以在模型中使用实例方法：

#app/models/model.rb
class Model < ActiveRecord::Base
   def percentage
      value = 0
      values = [[:date_of_birth, 15], [:gender, 15], [:relationship_status,10], [:language,10], [:qualification, 10]]
      values.each do |attr,val|
          value += val if self.send(attr).present?
      end
      value += self.interests.count >= 10 ? 10 : self.interests.count*5 if self.interests.present?
      # Rails should return the value of the last line, which is the "value" var
   end
end

这将允许您使用@user.percentage ，其中@user是您的模型实例@user 。

Answer 4

就我个人而言，我认为“减少行数”不是一个好主意，但是如果您希望代码减少行数，则可以这样编写：

percentage = 0; if date_of_birth.present? then percentage += 15 end; if gender.present? then percentage += 15 end; if relationship_status.present? then percentage += 10 end; if language.present? then percentage += 10 end; if qualification.present? then percentage += 10 end; if interests.present? then if interests.count >= 10 then percentage += 10 else percentage += interests.count*5 end end

在Ruby中，您可以（几乎）始终用分号替换换行符，以使代码适合较少的行。 实际上， 每个 Ruby程序始终可以在一行上编写。

Answer 5

inc_att = ["date_of_birth", "gender", "relationship_status" , "language", "qualification", "interests"]

inc_att.each do |s|

  if self[s].present? && (s == "date_of_birth" || s == "gender")
      percentage += 15
  elsif self[s].present? && s == "interests" && self[s].count < 10
      percentage += self[s].count * 5
  else
      percentage += 10 if self[s].present?
  end

end 

看看吧

Answer 6

inc_att = ["date_of_birth", "gender", "relationship_status" , "language",   "qualification", "interests"]

inc_att.each do |s|

if self[s].present? && (s == "date_of_birth" || s == "gender")
  percentage += 15
elsif self[s].present? && s == "interests" && self[s].count < 10
  percentage += self[s].count * 5
else
  percentage += 10 if self[s].present?
end

end 

Answer 7

受到@sawa的答案的启发：

counts = interests.count.to_i
percentage = (counts >= 10 ? 10 : (counts * 5)) + 
  [
    date_of_birth.present?       && 15,
    gender.present?              && 15,
    relationship_status.present? && 10,
    language.present?            && 10,
    qualification.present?       && 10,
  ].select(&:itself).sum