preg_match
Name
preg_match — Performs the regular expression match
against the specified string.
Synopsis
int preg_match(pattern, subject[, matches]);
string pattern: Regex
pattern to match
string subject: String to
search using the pattern
array matches (optional):
Array in which to store the search results
Returns
1 if a match is found; 0 otherwise
Description
This function tries to find the first match for the
regular expression pattern in the supplied subject string. If the matches parameter is supplied, it should
be a valid variable, such as $matches, since the
function forces it to be passed by reference. Existing
contents of this variable are overwritten with the
results of the successful search. $matches[0]
contains the text from the subject string that matched
the full pattern; the rest of the entries have the pieces
of the subject string matching the parenthesized
subpatterns.
If it's necessary to find all matches instead of just
one, use preg_match_all() instead.
Version
Existing since version 3.0.9
Example
Example 1128. Check whether a
filename ends in .txt or.doc
if (preg_match('!\.(doc|txt)$!', $filename)) {
// it does
}
else {
// it doesn't
}
Example 1129. Capture the
price from user input
if (preg_match('/\$(\d+\.\d{1,2}\b|\.\d{1,2}\b|\d+(?!\.))/', $input, $match)) {
$price = $match[1];
echo "Entered price was: $price\n";
}
else {
echo "Could not find a valid price\n";
}
PHP Functions Essential Reference. Copyright © 2002 by New Riders Publishing
(Authors: Zak Greant, Graeme Merrall, Torben Wilson, Brett Michlitsch).
This material may be distributed only subject to the terms and conditions set forth
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http://www.opencontent.org/openpub/).
The authors of this book have elected not to choose any options under the OPL. This online book was obtained
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and is designed to provide information about the PHP programming language, focusing on PHP version 4.0.4
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