Question

我正在研究这段代码，以使其更短，以便于学习或阅读，并且我已经应用干练和扎实的原理，所以您能帮助我如何重构此ruby on rails代码吗？包含一些if语句来执行此操作。因此使用这些原理，它变得更易于阅读和缩短。

if brand.rating = high
  if price_reference < 15
    price_suggestion = (price_reference - product_database.shipping_cost * 0.75) * 1.1
    price_original = price_suggestion
  elsif price_reference < 25
    price_suggestion = (price_reference - product_database.shipping_cost * 0.775) * 1.1
    price_original = price_suggestion
  elsif price_reference < 50
    price_suggestion = (price_reference - product_database.shipping_cost * 0.8) * 1.1
    price_original = price_suggestion
  elsif price_reference < 75
    price_suggestion = (price_reference - product_database.shipping_cost * 0.825) * 1.1
    price_original = price_suggestion
  elsif price_reference < 100
    price_suggestion = (price_reference - product_database.shipping_cost * 0.85) * 1.1
    price_original = price_suggestion
  elsif price_reference < 200
    price_suggestion = (price_reference - product_database.shipping_cost * 0.875) * 1.1
    price_original = price_suggestion
  elsif price_reference < 400
    price_suggestion = (price_reference - product_database.shipping_cost * 0.9) * 1.1
    price_original = price_suggestion
  elsif price_reference < 600
    price_suggestion = (price_reference - product_database.shipping_cost * 0.925) * 1.1
    price_original = price_suggestion
  else
    price_suggestion = (price_reference - product_database.shipping_cost * 0.95) * 1.1
    price_original = price_suggestion
elsif brand.rating = low
  if price_reference < 15
    price_suggestion = (price_reference - product_database.shipping_cost * 0.75) * 0.9
    price_original = price_suggestion
  elsif price_reference < 25
    price_suggestion = (price_reference - product_database.shipping_cost * 0.775) * 0.9
    price_original = price_suggestion
  elsif price_reference < 50
    price_suggestion = (price_reference - product_database.shipping_cost * 0.8) * 0.9
    price_original = price_suggestion
  elsif price_reference < 75
    price_suggestion = (price_reference - product_database.shipping_cost * 0.825) * 0.9
    price_original = price_suggestion
  elsif price_reference < 100
    price_suggestion = (price_reference - product_database.shipping_cost * 0.85) * 0.9
    price_original = price_suggestion
  elsif price_reference < 200
    price_suggestion = (price_reference - product_database.shipping_cost * 0.875) * 0.9
    price_original = price_suggestion
  elsif price_reference < 400
    price_suggestion = (price_reference - product_database.shipping_cost * 0.9) * 0.9
    price_original = price_suggestion
  elsif price_reference < 600
    price_suggestion = (price_reference - product_database.shipping_cost * 0.925) * 0.9
    price_original = price_suggestion
  else
    price_suggestion = (price_reference - product_database.shipping_cost * 0.95) * 0.9
    price_original = price_suggestion
else
  if price_reference < 15
    price_suggestion = (price_reference - product_database.shipping_cost * 0.75) * 1
    price_original = price_suggestion
  elsif price_reference < 25
    price_suggestion = (price_reference - product_database.shipping_cost * 0.775) * 1
    price_original = price_suggestion
  elsif price_reference < 50
    price_suggestion = (price_reference - product_database.shipping_cost * 0.8) * 1
    price_original = price_suggestion
  elsif price_reference < 75
    price_suggestion = (price_reference - product_database.shipping_cost * 0.825) * 1
    price_original = price_suggestion
  elsif price_reference < 100
    price_suggestion = (price_reference - product_database.shipping_cost * 0.85) * 1
    price_original = price_suggestion
  elsif price_reference < 200
    price_suggestion = (price_reference - product_database.shipping_cost * 0.875) * 1
    price_original = price_suggestion
  elsif price_reference < 400
    price_suggestion = (price_reference - product_database.shipping_cost * 0.9) * 1
    price_original = price_suggestion
  elsif price_reference < 600
    price_suggestion = (price_reference - product_database.shipping_cost * 0.925) * 1
    price_original = price_suggestion
  else
    price_suggestion = (price_reference - product_database.shipping_cost * 0.95) * 1
    price_original = price_suggestion
end

Answer 1

也许像这样：

def suggest_price(price_reference, shipping_cost)
  [
     [15, 0.75],
     [25, 0.775],
     [50, 0.8],
     ... etc ...
  ].each do |price_point, shipping_modifier|
    if price_reference < price_point
      return price_reference - shipping_cost * shipping_modifier
    end
  end
  return price_reference - shipping_cost * 0.95
end

def price_modifier(brand)
  if brand.rating == high
    1.1 
  elsif brand.rating == low
    0.9
  else
    1
  end
end

price_original = price_modifier(brand) * suggest_price(price_reference, product_database.shipping_cost)

我并不是说那是完美的代码，但这是您可以使用的一种方式。您可能想要一个恒定的价格点和修饰符。

Answer 2

您可以应用一些OOP。在Brand类中，您可以使用一些.case语句使其更具可读性...

def prices
  case self.rating
    when 'high"
      case  
        when price_reference < 15
          (price_reference - product_database.shipping_cost * 0.75) * 1.1
        when price_reference < 25
          (price_reference - product_database.shipping_cost * 0.775) * 1.1
        when price_reference < 50
          (price_reference - product_database.shipping_cost * 0.8) * 1.1 
          etc...

    when 'low'
      case 
          etc...
    else
          etc...
  end
end

嵌套的case语句更易于阅读。另外，您正在执行许多不需要的变量重新分配。请记住，Ruby总是返回它评估的最后一条语句。因此，当您在Brand类的成员上调用方法时，可以像这样使用它：

brand = Brand.new(rating: 'high', price_reference: '25')
#let's assume product_database.shipping_cost = 5
brand.prices
 #returns the value 23.2375 which came from (25 - 5 * 0.775) * 1.1

有很多方法可以做到这一点。通过创建一些哈希字典来包含每个公式的值，然后进行变量替换来调用它们，您可以抽象出更多代码。尝试根据对象和方法进行操作。 Ruby中的所有内容都是某种对象，您可以创建方法来调用那些调用其他方法并使用其他对象的对象。

有没有办法应用干燥和固体的校长

2 个答案: