php preg_replace函数基础与实例代码

发布:smiling　来源: PHP粉丝网　添加日期：2014-09-20 09:33:59　浏览: 评论：0　

preg_replace(mixed $pattern,mixed $replacement,mixed $subject [, int $limit = -1 [, int &$count ]])主题为匹配搜索模式,替换要搜索的模式,它可以是一个字符串或一个字符串数组.

电子修饰符使preg_replace函数()替代后,适当引用作为参数是php代码进行替换,提示:请确保置换构成一个有效的php代码字符串,否则php将在包含preg_replace函数线()解析错误.

返回值:preg_replace函数()返回一个数组,如果这个问题的参数是一个数组或一个字符串,否则,如果找到匹配,新问题会产生,否则将返回主题不变或null如果发生错误.

实例一,代码如下:

$string = 'april 15, 2003';

$pattern = '/(w+) (d+), (d+)/i';

$replacement = '${1}1,$3';

echo preg_replace($pattern, $replacement, $string);

实例二,代码如下:

$string = 'the quick brown fox jumped over the lazy dog.';

$patterns = array();

$patterns[0] = '/quick/';

$patterns[1] = '/brown/';

$patterns[2] = '/fox/';

$replacements = array();

$replacements[2] = 'bear';

$replacements[1] = 'black';

$replacements[0] = 'slow';

echo preg_replace($patterns, $replacements, $string);

通过ksorting模式和替代,我们应该得到我们想要的,代码如下:

ksort($patterns);

ksort($replacements);

echo preg_replace($patterns, $replacements, $string);

更换几个值,代码如下:

$patterns = array ('/(19|20)(d{2})-(d{1,2})-(d{1,2})/',

'/^s*{(w+)}s*=/');

$replace = array ('//', '$ =');

echo preg_replace($patterns, $replace, '{startdate} = 1999-5-27');

过滤所有html标签,代码如下:

preg_replace("/(</?)(w+)([^>]*>)/e",

             "'\1'.strtoupper('\2').'\3'",

             $html_body);

过滤所有script,代码如下:

$user_agent = "mozilla/4.0 (compatible; msie 5.01; windows nt 5.0)";

$ch = curl_init();    // initialize curl handle

curl_setopt($ch, curlopt_url, $url); // set url to post to

curl_setopt($ch, curlopt_failonerror, 1);              // fail on errors

curl_setopt($ch, curlopt_followlocation, 1);    // allow redirects

curl_setopt($ch, curlopt_returntransfer,1); // return into a variable

curl_setopt($ch, curlopt_port, 80);            //set the port number

curl_setopt($ch, curlopt_timeout, 15); // times out after 15s

curl_setopt($ch, curlopt_useragent, $user_agent);

$document = curl_exec($ch);

$search = array('@<script[^>]*?>.*?</script>@si',  // strip out javascript教程 www.111cn.net

'@<style[^>]*?>.*?</style>@siu',    // strip style tags properly

'@<[/!]*?[^<>]*?>@si',            // strip out html tags

'@<![ss]*?–[ ]*>@',         // strip multi-line comments including cdata

'/s{2,}/',

);

$text = preg_replace($search, " ", html_entity_decode($document));

$pat[0] = "/^s+/";

$pat[2] = "/s+$/";

$rep[0] = "";

$rep[2] = " ";

$text = preg_replace($pat, $rep, trim($text));

//开源代码phpfensi.com

return $text;

}