preg_match Perform a regular expression match &reftitle.description; intpreg_match stringpattern stringsubject arraymatches intflags intoffset Searches subject for a match to the regular expression given in pattern. &reftitle.parameters; pattern The pattern to search for, as a string. subject The input string. matches If matches is provided, then it is filled with the results of search. $matches[0] will contain the text that matched the full pattern, $matches[1] will have the text that matched the first captured parenthesized subpattern, and so on. flags flags can be the following flag: PREG_OFFSET_CAPTURE If this flag is passed, for every occurring match the appendant string offset will also be returned. Note that this changes the return value in an array where every element is an array consisting of the matched string at index 0 and its string offset into subject at index 1. offset Normally, the search starts from the beginning of the subject string. The optional parameter offset can be used to specify the alternate place from which to start the search (in bytes). Using offset is not equivalent to passing substr($subject, $offset) to preg_match in place of the subject string, because pattern can contain assertions such as ^, $ or (?<=x). Compare: ]]> &example.outputs; while this example ]]> will produce Array ( [0] => def [1] => 0 ) ) ]]> &reftitle.returnvalues; preg_match returns the number of times pattern matches. That will be either 0 times (no match) or 1 time because preg_match will stop searching after the first match. preg_match_all on the contrary will continue until it reaches the end of subject. preg_match returns &false; if an error occurred. &reftitle.changelog; &Version; &Description; 4.3.3 The offset parameter was added 4.3.0 The PREG_OFFSET_CAPTURE flag was added 4.3.0 The flags parameter was added &reftitle.examples; ]]> ]]> ]]> &example.outputs; \w+): (?\d+)/', $str, $matches); print_r($matches); ?> ]]> &example.outputs; foobar: 2008 [name] => foobar [1] => foobar [digit] => 2008 [2] => 2008 ) ]]> &reftitle.notes; Do not use preg_match if you only want to check if one string is contained in another string. Use strpos or strstr instead as they will be faster. &reftitle.seealso; preg_match_all preg_replace preg_split