PHP preg_last_error() Function
Example
Use preg_last_error() to handle errors:
<?php
$str = 'The regular expression is invalid.';
$pattern = '/invalid//';
$match = @preg_match($pattern, $str, $matches);
if($match === false) {
// An error occurred
$err = preg_last_error();
if($err ==
PREG_INTERNAL_ERROR) {
echo 'Invalid regular
expression.';
}
} else if($match) {
// A match was
found
echo $matches[0];
} else {
// No matches were
found
echo 'No matches found';
}
?>
Definition and Usage
The preg_last_error() function returns an error code for the most recently evaluated regular expression. The returned
value will match one of the following constants:
| Constant | Description |
|---|---|
| PREG_NO_ERROR | No error occurred |
| PREG_INTERNAL_ERROR | There was an error evaluating the expression |
| PREG_BACKTRACK_LIMIT_ERROR | The number of backtracks needed to evaluate the expression exceeded the limit given in PHP's configuration |
| PREG_RECURSION_LIMIT_ERROR | The recursion depth needed to evaluate the expression exceeded the limit given in PHP's configuration |
| PREG_BAD_UTF8_ERROR | The input string contained invalid UTF-8 data |
| PREG_BAD_UTF8_OFFSET_ERROR | During evaluation, a string offset did not point to the first character of a multibyte UTF-8 symbol |
| PREG_JIT_STACKLIMIT_ERROR | The JIT compiler ran out of stack memory when trying to evaluate the expression |
Syntax
preg_last_error()
Technical Details
| Return Value: | Returns an error code for the most recently evaluated regular expression |
|---|---|
| PHP Version: | 5.2.0+ |
❮ PHP RegExp Reference
