I have a deep and long array (matrix). I only know the product ID. How found way to product?
Sample an array of (but as I said, it can be very long and deep):
Array( [apple] => Array( [new] => Array( [0] => Array([id] => 1) [1] => Array([id] => 2)) [old] => Array( [0] => Array([id] => 3) [1] => Array([id] => 4)) ) ) I have id: 3, and i wish get this: apple, old, 0
Thanks
You can use this baby:
function getById($id,$array,&$keys){ foreach($array as $key => $value){ if(is_array( $value )){ $result = getById($id,$value,$keys); if($result == true){ $keys[] = $key; return true; } } else if($key == 'id' && $value == $id){ $keys[] = $key; // Optional, adds id to the result array return true; } } return false; } // USAGE: $result_array = array(); getById( 3, $products, $result_array); // RESULT (= $result_array) Array ( [0] => id [1] => 0 [2] => old [3] => apple ) The function itself will return true on success and false on error, the data you want to have will be stored in the 3rd parameter.
You can use array_reverse(), link, to reverse the order and array_pop(), link, to remove the last item ('id')
Recursion is the answer for this type of problem. Though, if we can make certain assumptions about the structure of the array (i.e., 'id' always be a leaf node with no children) there's further optimizations possible:
<?php $a = array( 'apple'=> array( 'new'=> array(array('id' => 1), array('id' => 2), array('id' => 5)), 'old'=> array(array('id' => 3), array('id' => 4, 'keyname' => 'keyvalue')) ), ); // When true the complete path has been found. $complete = false; function get_path($a, $key, $value, &$path = null) { global $complete; // Initialize path array for first call if (is_null($path)) $path = array(); foreach ($a as $k => $v) { // Build current path being tested array_push($path, $k); // Check for key / value match if ($k == $key && $v == $value) { // Complete path found! $complete= true; // Remove last path array_pop($path); break; } else if (is_array($v)) { // **RECURSION** Step down into the next array get_path($v, $key, $value, $path); } // When the complete path is found no need to continue loop iteration if ($complete) break; // Teardown current test path array_pop($path); } return $path; } var_dump( get_path($a, 'id', 3) ); $complete = false; var_dump( get_path($a, 'id', 2) ); $complete = false; var_dump( get_path($a, 'id', 5) ); $complete = false; var_dump( get_path($a, 'keyname', 'keyvalue') ); 
global var and it'd be a much better example if you did.
static $complete variable declaration instead. Feel free to post your own solution!I tried this for my programming exercise.
<?php $data = array( 'apple'=> array( 'new'=> array(array('id' => 1), array('id' => 2), array('id' => 5)), 'old'=> array(array('id' => 3), array('id' => 4)) ), ); ####print_r($data); function deepfind($data,$findfor,$depth = array() ){ foreach( $data as $key => $moredata ){ if( is_scalar($moredata) && $moredata == $findfor ){ return $depth; } elseif( is_array($moredata) ){ $moredepth = $depth; $moredepth[] = $key; $isok = deepfind( $moredata, $findfor, $moredepth ); if( $isok !== false ){ return $isok; } } } return false; } $aaa = deepfind($data,3); print_r($aaa); If you create the array once and use it multiple times i would do it another way...
$id_to_info=array(); $id_to_info[1]=&array['apple']['new'][0]; $id_to_info[2]=&array['apple']['new'][2]; 
