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Comment by klochner | Hacker News Reader

Confident coding comes from understanding the language.

  Array({:foo=>1}).map{|h| h[:foo]}
  TypeError: Symbol as array index

  [{:foo=>1}].flatten.compact.map{|h| h[:foo]}
   => [1]

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I'm not sure what you're getting at here, other than that trying to treat an array of arrays as an array of Hashes is a bad idea.

I think the point is that Array(h) destroys the Hash, whereas [h].flatten will leave it intact, adding another unexpected gotcha to Array().

Array's terrible friend Integer() implicitly crashed my app in production before, so found that interesting to know; not necessarily related to your talk though. :)

[h].flatten on the other hand of course breaks horribly when someone decides that one of the values is meant to hold an array.

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