https://ruby-china.org/tdxh20 en-us <p>class BookInStock attr_reader :isbn attr_accessor :price def initialize(isbn, price) <a href="/isbn" class="user-mention" title="@isbn"><i>@</i>isbn</a> = isbn <a href="/price" class="user-mention" title="@price"><i>@</i>price</a> = Float(price) end def price_in_cents Integer(price*100 + 0.5) end def price_in_cents=(cents) price = cents / 100.0 end</p> <h2 id="...">...</h2> <p>end book = BookInStock.new("isbn1", 33.80) puts "Price = #{book.price}" puts "Price in cents = #{book.price_in_cents}" book.price_in_cents = 1234 puts "Price = #{book.price}" puts "Price in cents = #{book.price_in_cents}"</p> <p>看这段代码，能跑的，但是 price 的值没有赋进去，我知道因为 price = cents / 100.0 没有 写<a href="/price" class="user-mention" title="@price"><i>@</i>price</a>，但是这行能运行的，我想知道这个 price 的值到底赋到哪去了 price 这个变量在 price_in_cents 里没有出现过，那怎么可以用的么 </p> tdxh20 Fri, 20 Apr 2012 08:10:02 +0800 https://ruby-china.org/topics/2746 https://ruby-china.org/topics/2746