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Regular expression function preg__PHP tutorial in PHP
- WBOYOriginal
- 2016-07-15 13:21:421108browse
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/");
$str="Title: {title}
Author: {author}
Address: {url}";
Author: {author}
Address: {url}";
echo "
";
";
if($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 "
".$re."
";
".$re."
";
?>
Output:
[html
Welcome to my blog: http://blog.csdn.net/qsyzb< ;/a>
preg_split ( string pattern, string subject [, intlimit [, int flags]] )
Cut related content through regular expressions, similar to the explode cutting function learned before, but explode can only cut in one way and has limitations.
Example:
[php]
$mode='/[,.#]/';
$str='one,two.three#four';
if($tag=preg_split($mode,$str)){
print_r($tag);
}else{
echo "Replacement failed!";
}
?>
Output:
[html]
Array
(
[0] => one
[1] => two
[2] => three
[3] => four
)
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