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锁定老帖子 主题：nil的疑惑
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发表时间：2007-02-28
令：a = {:x => 1}
既然：a[:y] == nil 则应有：a == {:x => 1, :y => nil} 但上面的逻辑不成立。 如果a[:y]的结果是undefined，而不是nil，那么说得过去。 |
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发表时间：2007-02-28
dcaoyuan 写道 令：a = {:x => 1}
既然：a[:y] == nil 则应有：a == {:x => 1, :y => nil} 但上面的逻辑不成立。 如果a[:y]的结果是undefined，而不是nil，那么说得过去。 if a[:y] should be "undefined", what should params[:a] be? still "undefined". you still have the same problem. the only difference is that you give nil a nickname "undefined" |
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发表时间：2007-02-28
In case of none params[:a] given, params[:a] should also be "undefined", so, the default_options.merge(user_options) will work properly, it can still give out a result:
{:a => 1, :b => 1}. Actually it's Ruby who seems to give nil a nickname "undefined". |
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