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Re: NSDictionary trouble

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Re: NSDictionary trouble

Subject: Re: NSDictionary trouble
From: Jens Alfke <email@hidden>
Date: Tue, 19 Jan 2010 10:26:47 -0800


On Jan 19, 2010, at 10:09 AM, Paul Bruneau wrote:

When I want to find the key(s) for a given object, I use the - allKeysForObject method

This is fine, but keep in mind that it's a lot slower since it does a linear search instead of a hash lookup. (It's O(n) instead of O(1).)

If you're putting this in code you know in advance is extremely performance sensitive, or will operate on huge data sets; or if you profile it later and find this is a bottleneck; you should go to a reverse dictionary mapping instead.

—Jens_______________________________________________

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References:  
  >NSDictionary trouble (From: Shawn Rutledge <email@hidden>)
  >Re: NSDictionary trouble (From: Paul Bruneau <email@hidden>)




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