note 114735 added to function.prev

Some corrections to the previous function. - When prev() and next() distance is now calculated properly returning the 'closer' one. - When exact is false, and an item exists with the key searched for, it now returns that entry instead of next/prev closest - At ends of the array, sometimes when moving past using next() or prev(), it caused results to die. This was corrected. - Added field to result stating whether the match was 'exact' ('exact'=>true), or nearest ('exact'=>false) <?php function nearest($array, $value, $exact=false) { // Initialize Variables $next = false; $prev = false; $return = false; $arr_begin = false; $arr_end = false; $exact_match = false; if($exact && isset($array[$value])) { // If exact match found, and searching for exact (not nearest), return result. $return = Array($value=>$array[$value]); $exact_match = true; } elseif (!$exact && isset($array[$value])) { // If exact match found, and searching for nearest, return result. $return = Array($value=>$array[$value]); $exact_match = true; } else { if(!isset($array[$value]) && !$exact) { // Insert element that doesn't exist so nearest can be found $array[$value] = '-'; } // Sort array so injected record is near relative numerics ksort($array); // Sort array on key // Set start and end keys $arr_begin = key($array); end($array); $arr_end = key($array); reset($array); // Loop through array until match is found, then set $prev and $next to the respective keys if exist while ( !is_null($key = key($array)) ) { $val = current($array); if($key == $value) { if($value <> $arr_begin) { prev($array); // Get entry before this one $prev = key($array); } next($array); // Skip current entry as this was what we were looking for nearest to if($value <> $arr_end) { next($array); // Get entry after this one $next = key($array); } break; } next($array); } if($prev && $next) { if(($value - $prev) < ($next - $value)) { // Previous is closer $return = Array($prev=>$array[$prev]); } else { // Next is closer $return = Array($next=>$array[$next]); } } elseif ($prev || $next) { if($prev) { // Only Previous exists $return = Array($prev=>$array[$prev]); } elseif ($next) { // Only Next exists $return = Array($next=>$array[$next]); } } } // Return resulting Array(). $return is false if nothing matches the closest conditions, or if exact is specified and key does not exist. if($return) { return $return+Array('exact'=>$exact_match); } else { return false; } } ?> Just to clarify, this function will return either an Array() containing the $key=>$value pair of the result and 'exact'=>(bool) whether the match was exact or not. To access the $key=>$value pair, can be done as follows : <?php $result = nearest( ... ); // Just here for clarification of the position for the code that follows. if($result) { // Output the Key echo key($result); // Output the Value echo $result( key($result) ); // Output if exact match if($result['exact']) { echo 'This was an EXACT match'; } else { echo 'This result was found with fuzzy logic'; } } else { echo 'No result found'; } ?> ---- Server IP: 72.55.140.6 Probable Submitter: 74.14.8.106 ---- Manual Page -- http://php.net/manual/en/function.prev.php Edit -- https://master.php.net/note/edit/114735 Del: integrated -- https://master.php.net/note/delete/114735/integrated Del: useless -- https://master.php.net/note/delete/114735/useless Del: bad code -- https://master.php.net/note/delete/114735/bad+code Del: spam -- https://master.php.net/note/delete/114735/spam Del: non-english -- https://master.php.net/note/delete/114735/non-english Del: in docs -- https://master.php.net/note/delete/114735/in+docs Del: other reasons-- https://master.php.net/note/delete/114735 Reject -- https://master.php.net/note/reject/114735 Search -- https://master.php.net/manage/user-notes.php