php sort associative array by specific key [duplicate] - php

Question

This question already has answers here:
How can I sort arrays and data in PHP?
(14 answers)
Closed 6 years ago.
Problem: I have an associative multi-dimensional array with each key having an array inside. It looks like this:
array(3){
[1]=>
"id"=>1
"name"=>"Test #1"
"listorder"=>1
[6]=>
"id"=>6
"name"=>"Test #1"
"listorder"=>3
[2]=>
"id"=>2
"name"=>"Test #2"
"listorder"=>2
}
I need to sort this array by each array's listorder value without changing any of the key numbers. How can this be done?
I am currently trying this code which I got from a separate Stack overflow question.
function sort_array(){
foreach($array as $key => $row){
$listorder[$row["id"]] = $row["listorder"];
}
array_multisort($listorder, SORT_ASC, $array);
return $array;
}
But this specific code rewrites all of the key numbers. Is there another way to sort without changing anything?

Answer 1

The best possible way is to use uasort() function.
Try this:
$array = array(
1 => array(
"id"=>1,
"name"=>"Test #1",
"listorder"=>1
),
6 => array(
"id"=>6,
"name"=>"Test #1",
"listorder"=>3
),
2 => array(
"id"=>2,
"name"=>"Test #2",
"listorder"=>2
)
);
function sort_count($a, $b) {
if ($a['listorder'] === $b['listorder']) {
return 0;
} else {
return ($a['listorder'] > $b['listorder'] ? 1:-1);
}
}
$sorted_array = uasort($array, 'sort_count');
echo "<pre>";
print_r($array);
echo "</pre>";

Answer 2

you can try to sort by creating a new array, with array_keys:
function sort_array($array)
{
$keys = array_keys($array);
$out = array();
$listorder = array();
foreach($array as $key => $row)
{
$listorder[$row["id"]] = $row["listorder"];
}
array_multisort($listorder, SORT_ASC, $keys);
foreach($keys as $k)
{
$out[$k] = $array[$k];
}
return $out;
}
It should only sort the 'keys' array (which contain keys of array).
And then you rebuild the sorted $array in $out

Answer 3

You can try this short and sweet piece of code:
uasort($data,function($a,$b){
return strcmp($a["listorder"],$b["listorder"]);
});
print_r($data);
Working Demo is Here