Ruby，堆栈级别太深（SystemStackError）
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Ruby, stack level too deep (SystemStackError)
提问by daremkd
I have the following code:
我有以下代码：
class BookPrice
attr_accessor :price
def initialize(price)
@price = price
end
def price_in_cents
Integer(price*100 + 0.5)
end
end
b = BookPrice.new(2.20)
puts b.price_in_cents
This all works well and produces 220. But when I replace the second line attr_accessor :price with:
这一切都运行良好并产生 220。但是当我将第二行 attr_accessor :price 替换为：
def price
@price = price
end
I get stack level too deep (SystemStackError) error. What's going on? I know I can replace Integer(price*100 + 0.5) with @price instead of the method call price, but I want to keep it the way it is for OOP reasons. How can I make this code work the way it is without attr_accessor?
我得到堆栈级别太深 (SystemStackError) 错误。这是怎么回事？我知道我可以用 @price 而不是方法调用 price 替换 Integer(price*100 + 0.5) ，但由于 OOP 的原因，我想保持它的样子。我怎样才能让这段代码在没有 attr_accessor 的情况下工作？
回答by Arup Rakshit
Your below code
你下面的代码
def price
@price = price # <~~ method name you just defined with `def` keyword.
end
Creates never stopable recursion,.
创建永不停止的递归，。
How can I make this code work the way it is without attr_accessor?
我怎样才能让这段代码在没有 attr_accessor 的情况下工作？
You need to write as
你需要写成
def price=(price)
@price = price
end
def price
@price
end
回答by Autumnsault
You need to do:
你需要做：
@price = self.price
to differentiate between your object attribute priceand your method parameter price.
区分您的对象属性price和方法参数price。
回答by Maged Makled
read_attributeis what you are looking for
read_attribute是你要找的
def price
@price = read_attribute(:price)
end
