Ruby on rails 我如何用更少的行写这个条件?
我在我的模型中编写了以下代码:Ruby on rails 我如何用更少的行写这个条件?,ruby-on-rails,ruby,Ruby On Rails,Ruby,我在我的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.q
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
但是看起来不太好。这是一个小东西的大量代码。我想减少行数。您可以在线执行,如下所示:
percentage += 15 if self.date_of_birth.present?
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
与此相反:
if self.interests.count >= 10
percentage += 10
else
percentage += self.interests.count*5
end
可以使用三元运算符:
percentage += self.interests.count >= 10 ? 10 : self.interests.count*5
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是模型的实例变量。就个人而言,我不认为减少行数是个好主意,但如果您希望代码减少行数,可以这样编写:
percentage += 15 if self.date_of_birth.present?
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,几乎总是可以用分号替换换行符,以使代码适合更少的行。事实上,每个Ruby程序都可以写在一行上
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
从@sawa的答案中得到启发,来看看它:
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
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
为什么要匆忙选择答案?我喜欢这种技巧,但发现处理兴趣的路线不协调,甚至不和谐。如果删除该行,并将最后一行替换为“.compact.sum+interest\u cost,其中interest\u cost是一种方法,我会觉得更令人愉快。@CarySwoveland你可能是对的。但是,可能需要改进的是逻辑设计。这种方法的一个缺点是,如果要求和的任何值发生更改,您必须大量重写代码。是的,它只适合当前的要求。我同意行数减少不是一个好主意。语法正确的行数越少越好。每当我在一家商店的收银台看到少于10件商品的牌子时,它就会发出刺耳的声音。