preg_replacePodręcznik PHPPoprzedniNastępnypreg_replace (PHP 3>= 3.0.9, PHP 4 )preg_replace -- Perform a regular expression search and replaceDescriptionmixed preg_replace ( mixed pattern, mixed replacement, mixed subject [, int limit])
Searches subject for matches to
pattern and replaces them with
replacement. If
limit is specified, then only
limit matches will be replaced; if
limit is omitted or is -1, then all
matches are replaced.
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.
Notatka:
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.
Przykład 1. Using backreferences followed by numeric literals.<?php
$str = "April 15, 2003";
$pattern = "/(\w+) (\d+), (\d+)/i";
$replacement = "\${1}1,\$3";
print preg_replace($pattern, $replacement, $string);
/* Output
======
April1,2003
*/
?>
If matches are found, the new subject will
be returned, otherwise subject will be
returned unchanged.
Every parameter to preg_replace() (except
limit) can be an array.
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().
Przykład 2. 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";
$replacements[0] = "slow";
print preg_replace($patterns, $replacements, $string);
/* Output
======
The bear black slow jumped over the lazy dog.
*/
/* By ksorting patterns and replacements,
we should get what we wanted. */
ksort($patterns);
ksort($replacements);
print preg_replace($patterns, $replacements, $string);
/* Output
======
The slow black bear jumped over the lazy dog.
*/
?>
If subject is an array, then the search
and replace is performed on every entry of
subject, and the return value is an array
as well.
If pattern and
replacement are arrays, then
preg_replace() takes a value from each array
and uses them to do search and replace on
subject. If
replacement has fewer values than
pattern, then empty string is used for the
rest of replacement values. If pattern
is an array and replacement is a string,
then this replacement string is used for every value of
pattern. The converse would not make
sense, though.
/e modifier makes
preg_replace() treat the
replacement parameter as PHP code after
the appropriate references substitution is done. Tip: make sure
that replacement constitutes a valid PHP
code string, otherwise PHP will complain about a parse error at
the line containing preg_replace().
Przykład 3. Replacing several values$patterns = array ("/(19|20)(\d{2})-(\d{1,2})-(\d{1,2})/",
"/^\s*{(\w+)}\s*=/");
$replace = array ("\\3/\\4/\\1\\2", "$\\1 =");
print preg_replace ($patterns, $replace, "{startDate} = 1999-5-27");
This example will produce:
$startDate = 5/27/1999
Przykład 4. Using /e modifierpreg_replace ("/(<\/?)(\w+)([^>]*>)/e",
"'\\1'.strtoupper('\\2').'\\3'",
$html_body);
This would capitalize all HTML tags in the input text.
Przykład 5. Convert HTML to text// $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);
Notatka:
Parameter limit was added after PHP 4.0.1pl2.
See also preg_match(),
preg_match_all(), and
preg_split().
PoprzedniSpis treściNastępnypreg_replace_callbackPoczątek rozdziałupreg_split
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