Shulou(Shulou.com)06/02 Report--

This article will explain in detail what the regular expression performance optimization methods are, and the editor thinks it is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

The regular expression optimization mentioned here is mainly aimed at the NFA pattern regular expression which is commonly used at present. For more information, please refer to: regular expression matching parsing process discussion and analysis (regular expression matching principle). From the above example, we can infer that it affects NFA class regular expressions (common language: GNU Emacs,Java,ergp,less,more,.NET language

PCRE library,Perl,PHP,Python,Ruby,sed,vi) is actually mainly its "backtracking", reducing the number of "backtracking" (reducing the number of loop searches for the same character) is the main way to improve performance. Let's look at an example:

Source string: adsfadfsdasfsdafdsfsadfsa

Matching requirements, matching... . Everything in the tag, including changing the tag

Common way of writing (1), because [^]

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