Hash vs list
Jonathan Ellis
jonathan at carnageblender.com
Fri Apr 21 21:19:45 MDT 2006
On Fri, 21 Apr 2006 20:51:59 -0600, "Levi Pearson" <levi at cold.org> said:
> Anyway, what O-notation doesn't tell you is what the constant factors
> in the algorithm are. It's all about how the algorithm scales. This
> means that if you know your problem will always be a certain size,
> the optimal algorithm might be different than if you know your
> problem set will grow, depending on the constant factors.
However, PHP is brain-damaged and implements lists as hashes whose keys
are the counting numbers. (In PHP terminology, both lists and hashes
are "arrays.") So in PHP, looking something up in a hash _is_ always
faster than searching a list, since the search is a series of hash
lookups.
-Jonathan
--
C++ is history repeated as tragedy. Java is history repeated as farce. --Scott McKay
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