Array Multisort with a multidirectional array [duplicate] - php

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How can I sort arrays and data in PHP?
(14 answers)
Closed 7 years ago.
This one is baffling me at the moment, and I'm a little confused as to what it is doing.
So I have a multi directional array:
$h_info[69993] = array('price' => '1.00', 'url' => 'url', 'rating' => '4');
$h_info[85398] = array('price' => '3.00', 'url' => 'url', 'rating' => '2');
$h_info[34394] = array('price' => '9.00', 'url' => 'url', 'rating' => '0');
Now I have the following while loop
foreach ($h_info as $row) {
foreach ($row as $key => $value){
${$key}[] = $value; //Creates $price, $url... arrays.
}
}
array_multisort($price, SORT_ASC, $h_info);
Now this works, but it removes the $h_info id from the array and outputs
Array
(
[0] => Array
(
[price] => 39
[url] => url,
[rating] => 4.5
)
...
But i need the ID to stay - when I do this:
foreach ($h_info as $row => $id) {
foreach ($row as $key => $value){
${$key}[] = $value; //Creates $price, $url... arrays.
}
}
array_multisort($price, SORT_ASC, $h_info);
The sort no longer works, but outputs the array correctly:
Array
(
[69993] => Array
(
[price] => 39
[url] => url,
[rating] => 4.5
)
...

Answer 1

Try this
$h_info[69993] = array('price' => '1.00', 'url' => 'url', 'rating' => '4');
$h_info[85398] = array('price' => '3.00', 'url' => 'url', 'rating' => '2');
$h_info[34394] = array('price' => '9.00', 'url' => 'url', 'rating' => '0');
//intitalize array
$result = array(); // or $result = [];
//add your main key into "key" parameter of array
array_walk($h_info, function (&$value,$key) use (&$result) {
$arr_info = $value;
$arr_info['key'] = $key;
$result[] = $arr_info;
});
//sort in ascending order by price
usort($result, function($a, $b) {
if($a['price']==$b['price']) return 0;
return $b['price'] < $a['price']?1:-1; // return $a['price'] < $b['price']?1:-1;(note : if you need it in descending order)
});
echo "<pre>";
print_r($result);
?>
and you will get result like this
Array
(
[0] => Array
(
[price] => 1.00
[url] => url
[rating] => 4
[key] => 69993
)
[1] => Array
(
[price] => 3.00
[url] => url
[rating] => 2
[key] => 85398
)
[2] => Array
(
[price] => 9.00
[url] => url
[rating] => 0
[key] => 34394
)
)
in ascending order by price
if you need to know more information abouta array_walk() and usort() please check this links :
http://php.net/manual/en/function.array-walk.php
http://php.net/manual/en/function.usort.php