News Feed
Sections




News Archive
Looking for more information on how to do PHP the right way? Check out PHP: The Right Way

Michael Dowling:
Favor Hash Lookups Over Array Searches
March 21, 2014 @ 10:47:34

Michael Dowling has a recent post to his site comparing the performance of hash lookups versus array searches.

A common programming requirement is to match a string against a set of known strings. For example, let's say you were iterating over the words in a forum post and testing to see if a word is in a list of prohibited words. A common approach to this problem is to create an array of the known prohibited words and then use PHP's in_array() function to test if the string is found in the list. However, there's a simple optimization you can make to significantly improve the performance of the algorithm.

He includes two pieces of sample code - one showing the searching of an array using in_array and the other running an isset to locate a key. He points out that the in_array method is quite a bit slower than the hash (key) lookup and includes a benchmark script to prove it.The results are pretty clear, with the hash lookup coming in about 480% faster than the in_array. He also points out that as the size of the strings you're comparing grows, the performance of in_array drops even more.

0 comments voice your opinion now!
hash lookup search array inarray benchmark

Link: http://mtdowling.com/blog/2014/03/17/hash-lookups-over-array-search/

blog comments powered by Disqus

Similar Posts

Gonzalo Ayuso's Blog: Performance analysis of Stored Procedures with PDO and PHP

Doru Moisa's Blog: Static call versus Singleton call in PHP

Freek Lijten's Blog: Currently on PHP's internals...

RosSoft Blog: Tutorial - Web based search engine for Flickr

Richard Thomas' Blog: Direction of Zend Framework?


Community Events

Don't see your event here?
Let us know!


voicesoftheelephpant api series framework introduction release laravel example library install language php7 extension conference interview performance laravel5 podcast community opinion

All content copyright, 2015 PHPDeveloper.org :: info@phpdeveloper.org - Powered by the Solar PHP Framework