programmer group

On efficiency greedy, non greedy and backtracking of regular expressions

First of all, what is the greedy regular expression, what is non greedy? Or what is the matching priority quantifier and what is the ignoring priority quantifier?Well, I don’t know what the concept is. Let’s take an example.Some students want to filter between the content, that is to write regular and procedures. Copy codeThe code is as follows: $str = preg_ Replace (‘% < script >. +? < / script >%...

programmer group

JavaScript regular expression (1)

A long time ago, articles were migrated. In JavaScript, regular expressions are also objects. This pattern can be used for regexp’s exec and test methods as well as string’s match, replace, search, and split methods. Create regular expression The first uses regular expression literals. //example Var re = / A / I g m; // I case insensitive g global match m multiple lines The second calls the regexp constructor. Call the...

programmer group

Efficiency Greedy, Non-Greedy and Retrospective Analysis of PHP Regular Expressions (Recommendation)

Firstly, what is regular expression greed and what is non-greed? Or what is matching priority classifier and what is ignoring priority classifier? Well, I don’t know what the concept is. Let’s give an example. One of the students wanted to filter between the content, that is how to write rules and procedures. $str = preg_replace ('%<script>. +?</script>%i',', $str);//non-greedy Looks like it’s okay,...