php preg_replace函數基礎與實例代碼

2024-09-04 11:49:02

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preg_replace(mixed $pattern,mixed $replacement,mixed $subject [, int $limit = -1 [, int &$count ]])主題為匹配搜索模式,替換要搜索的模式,它可以是一個字符串或一個字符串數組.

電子修飾符使preg_replace函數()替代后,適當引用作為參數是php代碼進行替換,提示:請確保置換構成一個有效的php代碼字符串,否則php將在包含preg_replace函數線()解析錯誤.

返回值:preg_replace函數()返回一個數組,如果這個問題的參數是一個數組或一個字符串,否則,如果找到匹配,新問題會產生,否則將返回主題不變或null如果發生錯誤.

實例一,代碼如下:

$string = 'april 15, 2003';

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

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

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

實例二,代碼如下:

$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);

通過ksorting模式和替代,我們應該得到我們想要的,代碼如下:

ksort($patterns);

ksort($replacements);

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

更換幾個值,代碼如下:

$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');

過濾所有html標簽,代碼如下:

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

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

             $html_body);

過濾所有script,代碼如下:

$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));

//開源代碼Vevb.com

return $text;

}