How to sort multidimensional array in PHP - php

Question

I have tried almost all suggestions online, and I really can't figure out how to sort this SESSION array.
I want it sorted by "itemname"..
I have and want this output, but I need the itemname to determine which item array come first.
Array
(
[person] => Array
(
[namex] => Array
(
[itema] => Array
(
[itemid] => 43
[itemname] => def
)
[itemc] => Array
(
[itemid] => 33
[itemname] => abc
)
[itemg] => Array
(
[itemid] => 29
[itemname] => ghi
)
)
[namey] => Array
(
[itemj] => Array
(
[itemid] => 12
[itemname] => abc
)
[iteme] => Array
(
[itemid] => 44
[itemname] => jkl
)
[itemr] => Array
(
[itemid] => 20
[itemname] => rst
)
)
)
)
So, "person" stays the same, but name, item, itemid and itemname is always different.
Can anyone help me sort this by itemname?
I need the array to be like this, so can't change it up.
Also.. I need to access it later in a foreach, so I can print out the items.

Answer 1

As pointed out in the comments to the question the desired output is not really defined. You'd have to give a specific definition of the output, without that we have to assume what you probably are looking for:
<?php
$data = [
"person" => [
"namex" => [
"itema" => [
"itemid" => 43,
"itemname" => "def"
],
"itemc" => [
"itemid" => 33,
"itemname" => "abc"
],
"itemg" => [
"itemid" => 29,
"itemname" => "ghi"
]
],
"namey" => [
"itemj" => [
"itemid" => 12,
"itemname" => "abc"
],
"iteme" => [
"itemid" => 44,
"itemname" => "jkl"
],
"itemr" => [
"itemid" => 20,
"itemname" => "rst"
]
]
]
];
foreach ($data["person"] as $personName => &$person) {
uasort($person, function($a, $b) {
return $a["itemname"] > $b["itemname"];
});
}
print_r($data);
The obvious output is:
Array
(
[person] => Array
(
[namex] => Array
(
[itemc] => Array
(
[itemid] => 33
[itemname] => abc
)
[itema] => Array
(
[itemid] => 43
[itemname] => def
)
[itemg] => Array
(
[itemid] => 29
[itemname] => ghi
)
)
[namey] => Array
(
[itemj] => Array
(
[itemid] => 12
[itemname] => abc
)
[iteme] => Array
(
[itemid] => 44
[itemname] => jkl
)
[itemr] => Array
(
[itemid] => 20
[itemname] => rst
)
)
)
)

Answer 2

Assuming the input from the example is represented via array as:
<?php
$array = [
'person' => [
'namex' => [
'itema' => [
'itemid' => 43,
'itemname' => 'def'
],
'itemb' => [
'itemid' => 33,
'itemname' => 'abc'
],
'itemc' => [
'itemid' => 29,
'itemname' => 'ghi'
],
],
'namey' => [
'itema' => [
'itemid' => 12,
'itemname' => 'abc'
],
'itemb' => [
'itemid' => 44,
'itemname' => 'jkl'
],
'itemc' => [
'itemid' => 20,
'itemname' => 'rst'
],
],
]
];
You could do use array_multisort in a loop:
$ids = [];
foreach($array as $key => $value) {
foreach ($value as $newKey => $value2) {
$ids[$newKey] = array_column($value2, 'itemname');
array_multisort($ids[$newKey], SORT_NATURAL, $array[$key][$newKey]);
}
}
This will output
array(1) {
'person' =>
array(2) {
'namex' =>
array(3) {
'itemb' =>
array(2) {
'itemid' =>
int(33)
'itemname' =>
string(3) "abc"
}
'itema' =>
array(2) {
'itemid' =>
int(43)
'itemname' =>
string(3) "def"
}
'itemc' =>
array(2) {
'itemid' =>
int(29)
'itemname' =>
string(3) "ghi"
}
}
'namey' =>
array(3) {
'itema' =>
array(2) {
'itemid' =>
int(12)
'itemname' =>
string(3) "abc"
}
'itemb' =>
array(2) {
'itemid' =>
int(44)
'itemname' =>
string(3) "jkl"
}
'itemc' =>
array(2) {
'itemid' =>
int(20)
'itemname' =>
string(3) "rst"
}
}
}
}