PHP preg_match() Function
Example
Use a regular expression to do a case-insensitive search for "w3schools" in a string:
<?php
$str = "Visit W3Schools";
$pattern = "/w3schools/i";
echo
preg_match($pattern, $str);
?>
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Definition and Usage
The preg_match() function returns whether a
match was found in a string.
Syntax
preg_match(pattern, input, matches, flags, offset)
Parameter Values
| Parameter | Description |
|---|---|
| pattern | Required. Contains a regular expression indicating what to search for |
| input | Required. The string in which the search will be performed |
| matches | Optional. The variable used in this parameter will be populated with an array containing all of the matches that were found |
| flags | Optional. A set of options that change how the matches array is
structured:
|
| offset | Optional. Defaults to 0. Indicates how far into the string to begin searching. The preg_match() function will not find matches that occur before the position given in this parameter |
Technical Details
| Return Value: | Returns 1 if a match was found, 0 if no matches were found and false if an error occurred |
|---|---|
| PHP Version: | 4+ |
| Changelog: | PHP 7.2 - Added the PREG_UNMATCHED_AS_NULL flag PHP 5.3.6 - The function returns false when the offset is longer than the length of the input PHP 5.2.2 - Named subpatterns can use the (?'name') and (? <name>) syntax in addition to the previous (?P<name>) |
More Examples
Example
Use PREG_OFFSET_CAPTURE to find the position in the input string in which the matches were found:
<?php
$str = "Welcome to W3Schools";
$pattern = "/w3schools/i";
preg_match($pattern, $str, $matches, PREG_OFFSET_CAPTURE);
print_r($matches);
?>
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❮ PHP RegExp Reference
