php-regexHow to get last matched occurrence in PHP regex?

The preg_match_all function in PHP can be used to get the last matched occurrence in a regular expression. This function takes three parameters: the pattern, the subject string, and an array to store the matches. The fourth parameter can be used to specify the flags, such as PREG_OFFSET_CAPTURE which will capture the offset of the last matched occurrence.

$subject = 'This is a test string';
$pattern = '/\w+/';

preg_match_all($pattern, $subject, $matches, PREG_OFFSET_CAPTURE);

echo $matches[0][count($matches[0])-1][0]; // Output: string

The code above will capture all the matches of the pattern /\w+/ in the subject string This is a test string. The PREG_OFFSET_CAPTURE flag will capture the offset of each match. The last matched occurrence can then be accessed by using the count($matches[0])-1 index of the $matches array.

• $subject: The subject string to be matched against the pattern.
• $pattern: The regular expression pattern.
• $matches: An array to store the matches.
• PREG_OFFSET_CAPTURE: A flag to capture the offset of each match.
• count($matches[0])-1: The index of the last matched occurrence.

Helpful links

• PHP preg_match_all
• PHP preg_match

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