Regular expression function preg__PHP tutorial in PHP-PHP Tutorial-php.cn

preg_match(); //Used for regular expression matching, and only matches once

preg_match_all(); // Used for regular expression matching, all matches that match the rules will be matched

preg_replace(); //Regular expression replacement function

preg_splite(); //Regular split function

preg_match (mode, string subject, arraymatches)

where mode is a regular rule, string subject is the string to be matched, and arraymatches is the array of matching results

Example:

[php]

$mode='/[89]/';//match 8 or 9

$str="djfkdsjk10903990sjdfdk";

preg_match($mode,$str,$arr);

print_r($arr);

Output:

[html]

Array ( [0] => 9 )

preg_match_all (mode, string subject, arraymatches)

This function is similar to the preg_match_all() function, but this function will match all content that meets the requirements and store it in a string.

Example:

[php]

$mode='/[89]/';//match 8 or 9

$str="dj33f44k88dsjk10903990sjdfdk";

preg_match_all($mode,$str,$arr);

print_r($arr);

Output:

[html]

Array ( [0] => Array ( [0] => 8 [1] => 8 [2] => 9 [3] => 9 [4] => 9 ) )

preg_replace ( mixed pattern, mixed replacement, mixed subject [, int limit] )

Replace related content through regular expressions, similar to the str_replace string replacement learned before, but the function is stronger than it.

Features: 1. The replacement content can be a regular expression or an array regular expression

2. The replacement content can be solved by using the modifier e to replace the execution content

Usage: to replace some more complex content, and can also be used for content conversion

Example 1 - Array regularization:

[php]

$mode=array('/{title}/','/{author}/','/{url}/');

$re=array("code cloud","qianshou","http://codecloud.duapp.com/");

$str="Title: {title}
Author: {author}
Address: {url}";

echo "

if($tag=preg_replace($mode,$re,$str)){

echo $tag;

}else{

echo "Replacement failed!";

}

Output:

[html]

Title: code cloud

Author: qianshou

Address: http://codecloud.duapp.com/

Example 2 - Replacement of ubb code:

[php]

$str="Welcome to my blog: [url]http://blog.csdn.net/qsyzb[/url]";

$re=preg_replace('/[url](.*)[/url]/',"\1",$ str);

echo "

".$re."

Output:

[html

Welcome to my blog: http://blog.csdn.net/qsyzb< ;/a>

preg_split ( string pattern, string subject [, intlimit [, int flags]] )

Example:

[php]

$mode='/[,.#]/';

$str='one,two.three#four';

if($tag=preg_split($mode,$str)){

print_r($tag);

}else{

echo "Replacement failed!";

source：php.cn

Previous article：Personal summary of php array related functions_PHP tutorial Next article：cakephp notes - view layer_PHP tutorial

Statement of this Website

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn