ZALOGUJ SIĘ

KURSY, DOKUMENTACJE

Własne:
• XHTML/CSS
• JavaScript
• ActionScript
• WML, RSS, SSI

Pozostałe:
• PHP
• MySQL
• Java API
• więcej...

użytkowników online: 121

W CZYM MOGĘ POMÓC?

OPINIE UŻYTKOWNIKÓW

Uważam, że serwis jest najlepszy na świecie. Wykonany rzetelnie, a wszystkie skrypty sa dopracowane. Zamieszczony materiał godny mistrza. Jestem programistą od wielu lat i bez tego serwisu nie istnieje. Upraszacza życie każdemu programiście. Imponujący jest fakt, że do twórcy serwisu zawsze można się zwrócić z prośbą o pomoc i uzyskuje się ją w bardzo krótkim czasie. Najważniejsze w tym wszystkim jest to, że można korzystać z witryny za symboliczną opłatą.

Marcin Kowalski
Multinet Polska

więcej opinii klientów

GALERIA FOTOGRAFII

zobacz inne zdjęcia

PODRĘCZNIK PHP 5.x, 4.x, 3.x - częściowo spolszczony / źródło: www.php.net

[Spis] [A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [X] [W] [Z]

preg_replace

(PHP 3 >= 3.0.9, PHP 4, PHP 5)

preg_replace -- Perform a regular expression search and replace

Opis

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

Searches subject for matches to pattern and replaces them with replacement.

Replacement may contain references of the form \\n or (since PHP 4.0.4) $n, with the latter form being the preferred one. Every such reference will be replaced by the text captured by the n'th parenthesized pattern. n can be from 0 to 99, and \\0 or $0 refers to the text matched by the whole pattern. Opening parentheses are counted from left to right (starting from 1) to obtain the number of the capturing subpattern.

When working with a replacement pattern where a backreference is immediately followed by another number (i.e.: placing a literal number immediately after a matched pattern), you cannot use the familiar \\1 notation for your backreference. \\11, for example, would confuse preg_replace() since it does not know whether you want the \\1 backreference followed by a literal 1, or the \\11 backreference followed by nothing. In this case the solution is to use \${1}1. This creates an isolated $1 backreference, leaving the 1 as a literal.

If subject is an array, then the search and replace is performed on every entry of subject, and the return value is an array as well.

The e modifier makes preg_replace() treat the replacement parameter as PHP code after the appropriate references substitution is done. Tip: make sure that replacement constitutes a valid PHP code string, otherwise PHP will complain about a parse error at the line containing preg_replace().

Parametry

pattern: The pattern to search for. It can be either a string or an array with strings.
replacement: The string or an array with strings to replace. If this parameter is a string and the pattern parameter is an array, all pattens will be replaced by that string. If both pattern and replacement parameters are arrays, each pattern will be replaced by the replacement counterpart. If there are less keys in the replacement array than in the pattern array, the excedent patterns will be replaced by an empty string.
subject: The string or an array with strings to search and replace.
limit: The maximum possible replacements for each pattern in each subject string. Defaults to -1 (no limit).
count: If specified, this variable will be filled with the number of replacements done.

Zwracane wartości

preg_replace() returns an array if the subject parameter is an array, or a string otherwise.

If matches are found, the new subject will be returned, otherwise subject will be returned unchanged.

Rejestr zmian

Wersja	Opis
4.0.1pl2	Added the `limit` parameter
4.0.4	Added the '$n' form for the `replacement` parameter
5.1.0	Added the `count` parameter

Przykłady

Przykład 1. Convert HTML to text


<?php

// $document should contain an HTML document.

// This will remove HTML tags, javascript sections

// and white space. It will also convert some

// common HTML entities to their text equivalent.

$search = array ('@<script[^>]*?>.*?</script>@si', // Strip out javascript

                 '@<[\/\!]*?[^<>]*?>@si',          // Strip out HTML tags

                 '@([\r\n])[\s]+@',                // Strip out white space

                 '@&(quot|#34);@i',                // Replace HTML entities

                 '@&(amp|#38);@i',

                 '@&(lt|#60);@i',

                 '@&(gt|#62);@i',

                 '@&(nbsp|#160);@i',

                 '@&(iexcl|#161);@i',

                 '@&(cent|#162);@i',

                 '@&(pound|#163);@i',

                 '@&(copy|#169);@i',

                 '@&#(\d+);@e');                    // evaluate as php



$replace = array ('',

                  '',

                  '\1',

                  '"',

                  '&',

                  '<',

                  '>',

                  ' ',

                  chr(161),

                  chr(162),

                  chr(163),

                  chr(169),

                  'chr(\1)');



$text = preg_replace($search, $replace, $document);

?>

Przykład 2. Using backreferences followed by numeric literals


<?php

$string = 'April 15, 2003';

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

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

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

?>

Powyższy przykład wyświetli:

April1,2003

Przykład 3. Using indexed arrays with preg_replace()


<?php

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

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

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

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

$replacements[2] = 'bear';

$replacements[1] = 'black';

$replacements[0] = 'slow';

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

?>

Powyższy przykład wyświetli:

The bear black slow jumped over the lazy dog.

By ksorting patterns and replacements, we should get what we wanted.


<?php

ksort($patterns);

ksort($replacements);

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

?>

Powyższy przykład wyświetli:

The slow black bear jumped over the lazy dog.

Przykład 4. Replacing several values


<?php

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

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

$replace = array ('\3/\4/\1\2', '$\1 =');

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

?>

Powyższy przykład wyświetli:

$startDate = 5/27/1999

Przykład 5. Using the 'e' modifier


<?php

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

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

             $html_body);

?>

This would capitalize all HTML tags in the input text.

Przykład 6. Strip whitespace

This example strips excess whitespace from a string.


<?php

$str = 'foo   o';

$str = preg_replace('/\s\s+/', ' ', $str);

// This will be 'foo o' now

echo $str;

?>

Przykład 7. Using the count parameter


<?php

$count = 0;



echo preg_replace(array('/\d/', '/\s/'), '*', 'xp 4 to', -1 , $count);

echo $count; //3

?>

Powyższy przykład wyświetli:

xp***to
3

Notatki

Notatka: When using arrays with pattern and replacement, the keys are processed in the order they appear in the array. This is not necessarily the same as the numerical index order. If you use indexes to identify which pattern should be replaced by which replacement, you should perform a ksort() on each array prior to calling preg_replace().

Patrz także

preg_match()

preg_replace_callback()

preg_split()

User Contributed Notes

Rebort
02-Feb-2006 08:51


Following up on pietjeprik at gmail dot com's great string to parse [url] bbcode: 

<?php

$url = '[url=http://www.foo.org]The link[/url]';

$text = preg_replace("/\[url=(\W?)(.*?)(\W?)\](.*?)\[\/url\]/", '<a href="$2">$4</a>', $url);

?>



This allows for the user to enter variations: 



[url=http://www.foo.org]The link[/url]

[url="http://www.foo.org"]The link[/url]

[url='http://www.foo.org']The link[/url]



or even



[url=#http://www.foo.org#]The link[/url]

[url=!http://www.foo.org!]The link[/url]

31-Jan-2006 07:23


Uh-oh. When I looked at the text in the preview, I had to double the number of backslashes to make it look right. 

I'll try again with my original text:



$full_text = preg_replace('/\[p=(\d+)\]/e',

  "\"<a href=\\\"./test.php?person=$1\\\">\"

    .get_name($1).\"</a>\"",

   $short_text);



I hope that it comes out correctly this time :-)

leif at solumslekt dot org
31-Jan-2006 05:24


I've found a use for preg_replace. If you've got eg. a database with persons assiciated with numbers, you may want to input links in a kind of shorthand, like [p=12345], and have it expanded to a full url with a name in it.



This is my solution:



$expanded_text = preg_replace('/\\[p=(\d+)\\]/e',

    "\\"<a href=\\\\\\"./test.php?person=$1\\\\\\">\\".get_name($1).\\"</a&>\\"",

        $short_text);



It took me some time to work out the proper number of quotes and backslashes.



regards, Leif.

SG_01
20-Jan-2006 01:43


Re: wcc at techmonkeys dot org



You could put this in 1 replace for faster execution as well:



<?php



/*

 * Removes all blank lines from a string.

 */

function removeEmptyLines($string)

{

   return preg_replace("/(^[\r\n]*|[\r\n]+)[\s\t]*[\r\n]+/", "\n", $string);

}



?>

05-Jan-2006 11:09


First, I have no idea about regexp, all I did has been through trial and error, 

I wrote this function which tries to clean crappy ms word html, I use it to clean user pasted code to online wysiwyg online editors from ms word.

There