note 112605 added to ref.strings

I was looking for a function to find the common substring in 2 different strings. I tried both the mb_string_intersect and string_intersect functions listed here but didn't work for me. I found the algorithm at http://en.wikibooks.org/wiki/Algorithm_implementation/Strings/Longest_common_substring#PHP so here I post you the function <?php /** * Finds the matching string between 2 strings * * @param string $string1 * @param string $string2 * @param number $minChars * * @return NULL|string * * @link http://en.wikibooks.org/wiki/Algorithm_implementation/Strings/Longest_common_substring#PHP */ function string_intersect($string_1, $string_2) { $string_1_length = strlen($string_1); $string_2_length = strlen($string_2); $return = ""; if ($string_1_length === 0 || $string_2_length === 0) { // No similarities return $return; } $longest_common_subsequence = array(); // Initialize the CSL array to assume there are no similarities for ($i = 0; $i < $string_1_length; $i++) { $longest_common_subsequence[$i] = array(); for ($j = 0; $j < $string_2_length; $j++) { $longest_common_subsequence[$i][$j] = 0; } } $largest_size = 0; for ($i = 0; $i < $string_1_length; $i++) { for ($j = 0; $j < $string_2_length; $j++) { // Check every combination of characters if ($string_1[$i] === $string_2[$j]) { // These are the same in both strings if ($i === 0 || $j === 0) { // It's the first character, so it's clearly only 1 character long $longest_common_subsequence[$i][$j] = 1; } else { // It's one character longer than the string from the previous character $longest_common_subsequence[$i][$j] = $longest_common_subsequence[$i - 1][$j - 1] + 1; } if ($longest_common_subsequence[$i][$j] > $largest_size) { // Remember this as the largest $largest_size = $longest_common_subsequence[$i][$j]; // Wipe any previous results $return = ""; // And then fall through to remember this new value } if ($longest_common_subsequence[$i][$j] === $largest_size) { // Remember the largest string(s) $return = substr($string_1, $i - $largest_size + 1, $largest_size); } } // Else, $CSL should be set to 0, which it was already initialized to } } // Return the list of matches return $return; } ---- Server IP: 69.147.83.199 Probable Submitter: 190.148.81.59 ---- Manual Page -- http://php.net/manual/en/ref.strings.php Edit -- https://master.php.net/note/edit/112605 Del: integrated -- https://master.php.net/note/delete/112605/integrated Del: useless -- https://master.php.net/note/delete/112605/useless Del: bad code -- https://master.php.net/note/delete/112605/bad+code Del: spam -- https://master.php.net/note/delete/112605/spam Del: non-english -- https://master.php.net/note/delete/112605/non-english Del: in docs -- https://master.php.net/note/delete/112605/in+docs Del: other reasons-- https://master.php.net/note/delete/112605 Reject -- https://master.php.net/note/reject/112605 Search -- https://master.php.net/manage/user-notes.php