Creating Array Key Name with Dynamic Array - php

Question

I am trying to get the example below to have key names for each dimension so it would look more like this:
Array
(
[Mobile] => Array
(
[0] => Array
(
[product_id] => 007
[product_name] => Blackberry R-900 Mobile
[product_price] => £450
[product_status] => 1
[product_category] => Mobile
)
Instead of the example below,
I have included the class that I am using to create the array into a categorized array and the usage of it.
The function appendNode in array2arraytree is where the algorithm actually creates the new array for each category.
Thanks for any help.
Example:
Array
(
[0] => Array
(
[0] => Array
(
[product_id] => 007
[product_name] => Blackberry R-900 Mobile
[product_price] => £450
[product_status] => 1
[product_category] => Mobile
)
[1] => Array
(
[product_id] => 001
[product_name] => Wespro Multi-SIM & Touch-screen Mobile
[product_price] => £150
[product_status] => 1
[product_category] => Mobile
)
[2] => Array
(
[product_id] => 004
[product_name] => Sigmatel MP4/MP3 + Camera Mobile
[product_price] => £150
[product_status] => 1
[product_category] => Mobile
)
)
[1] => Array
(
[0] => Array
(
[product_id] => 033
[product_name] => 8 GB Pendrive
[product_price] => £14.99
[product_status] => 0
[product_category] => Computers
)
[1] => Array
(
[product_id] => 334
[product_name] => 250 GB Portable Hard Drive
[product_price] => £79.99
[product_status] => 1
[product_category] => Computers
)
)
[2] => Array
(
[0] => Array
(
[product_id] => 033
[product_name] => The White Tiger – Aravind Adiga
[product_price] => £29.99
[product_status] => 1
[product_category] => Books
)
[1] => Array
(
[product_id] => 4501
[product_name] => The Final Reckoning - Sam Bourne
[product_price] => £19.99
[product_status] => 0
[product_category] => Books
)
[2] => Array
(
[product_id] => 034
[product_name] => The Final Reckoning - Sam Bourne
[product_price] => £15.79
[product_status] => 0
[product_category] => Books
)
)
)
Usage:
<?php
require_once("array2arraytree.php");
$arrProducts=array(
array(
"product_id" => "007",
"product_name" => "Blackberry R-900 Mobile",
"product_price" => "£450",
"product_status" =>"1",
"product_category" =>"Mobile"
),
array(
"product_id" => "033",
"product_name" => "8 GB Pendrive",
"product_price" => "£14.99",
"product_status" => "0",
"product_category" => "Computers"
),
array(
"product_id" => "033",
"product_name" => "The White Tiger – Aravind Adiga",
"product_price" => "£29.99",
"product_status" => "1",
"product_category" => "Books"
),
array(
"product_id" => "4501",
"product_name" => "The Final Reckoning - Sam Bourne",
"product_price" => "£19.99",
"product_status" => "0",
"product_category" => "Books"
),
array(
"product_id" => "001",
"product_name" => "Wespro Multi-SIM & Touch-screen Mobile",
"product_price" => "£150",
"product_status" => "1",
"product_category" => "Mobile"
),
array(
"product_id" => "004",
"product_name" => "Sigmatel MP4/MP3 + Camera Mobile",
"product_price" => "£150",
"product_status" => "1",
"product_category" => "Mobile"
),
array(
"product_id" => "034",
"product_name" => "The Final Reckoning - Sam Bourne",
"product_price" => "£15.79",
"product_status" => "0",
"product_category" => "Books"
),
array(
"product_id" => "334",
"product_name" => "250 GB Portable Hard Drive",
"product_price" => "£79.99",
"product_status" => "1",
"product_category" => "Computers"
)
);
$objTree=new Array2ArrayTree($arrProducts,"product_category");
$arrTree=$objTree->makeTree();
print("<pre>");
print_r($arrTree);
print("</pre>");
?>
Class Array2ArrayTree:
class Array2ArrayTree
{
public $arrOriginal = array();
public $arrDummy = array();
public $strKey = "";
public function __construct($arrData, $arrKey)
{
$this->arrOriginal = $arrData;
$this->strKey = $arrKey;
$this->arrDummy = array();
}
public function makeTree()
{
for ($i = 0; $i <= sizeof($this->arrOriginal) - 1; $i++) {
$keyPosition = $this->searchKey($this->arrOriginal[$i][$this->strKey]);
if ($keyPosition == -1) {
$this->addNode($this->arrOriginal[$i]);
} else {
$this->appendNode($this->arrOriginal[$i], $keyPosition);
}
}
return $this->arrDummy;
}
function searchKey($strCurrentValue)
{
for ($i = 0; $i <= sizeof($this->arrDummy) - 1; $i++) {
if ($this->arrDummy[$i][0][$this->strKey] == $strCurrentValue) {
return $i;
}
}
return - 1;
}
function addNode($arrNode)
{
$this->arrDummy[sizeof($this->arrDummy)][0] = $arrNode;
}
function appendNode($arrNode, $keyPosition)
{
array_push($this->arrDummy[$keyPosition], $arrNode);
}
}
?>

Answer 1

Should be even simpler:
public function makeTree()
{
foreach($this->arrOriginal as $value) {
$this->arrDummy[$value[$this->strKey]][] = $value;
}
return $this->arrDummy;
}

Answer 2

I think this would work - map the array to get the keys you want, then use array_filter to get only the items in that category:
//get the keys you want:
$keys = array_unique(array_map(function($item) { return $item['product_category']; }, $array));
$return = [];
foreach($keys as $key) {
//filter the array to the one's in the current category, and reindex them to 0:
$return[$key] = array_values(array_filter($array, function($item) use ($key) {
return $item['product_category'] == $key;
}));
}