I have two servers; one running 5.6 and another that is running 7. Using this function on the two servers gets me different results when all of the values are the same.
<?php
$list = json_decode('{"706":2,"703":2,"702":2,"696":2,"658":2}', true);
print_r($list);
arsort($list);
echo "<br>";
print_r($list);
?>
PHP 5.6 results:
Array ( [706] => 2 [703] => 2 [702] => 2 [696] => 2 [658] => 2 )
Array ( [658] => 2 [696] => 2 [702] => 2 [703] => 2 [706] => 2 )
PHP 7 results:
Array ( [706] => 2 [703] => 2 [702] => 2 [696] => 2 [658] => 2 )
Array ( [706] => 2 [703] => 2 [702] => 2 [696] => 2 [658] => 2 )
arsort
(PHP 4, PHP 5, PHP 7, PHP 8)
arsort — Trie un tableau en ordre décroissant et conserve l'association des index
Description
Trie array sur place en ordre décroissant,
de telle manière que la corrélation entre les clés et les
valeurs soit conservée.
L'usage principal est lors de tri de tableaux associatifs où l'ordre des éléments est important.
Note:
Si deux membres se comparent comme égaux, ils maintiennent leur ordre original. Antérieur à PHP 8.0.0, leur ordre relatif dans le tableau trié n'est pas défini.
Note:
Réinitialise le pointeur interne du tableau au premier élément.
Liste de paramètres
-
array -
Le tableau d'entrée.
-
flags -
Le deuxième paramètre optionnel
flagspeut être utilisé pour modifier le comportement de tri en utilisant ces valeurs :Type de drapeaux de tri :
-
SORT_REGULAR- compare items normally; the details are described in the comparison operators section -
SORT_NUMERIC- compare les éléments numériquement -
SORT_STRING- compare les éléments comme des chaînes de caractères -
SORT_LOCALE_STRING- compare les éléments comme des chaînes de caractères, basé sur la locale courante. Ceci utilise la locale, qui peut être changée en utilisant setlocale() -
SORT_NATURAL- compare les éléments comme des chaînes de caractères utilisant "l'ordre naturel" comme natsort() -
SORT_FLAG_CASE- peut être combiné (OU bit à bit) avecSORT_STRINGouSORT_NATURALpour trier les chaînes sans tenir compte de la casse
-
Valeurs de retour
Retourne toujours true.
Historique
| Version | Description |
|---|---|
| 8.2.0 |
Le type de retour est maintenant true, auparavant il était bool.
|
Exemples
Exemple #1 Exemple avec arsort()
<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
arsort($fruits);
foreach ($fruits as $key => $val) {
echo "$key = $val\n";
}
?>L'exemple ci-dessus va afficher :
a = orange d = lemon b = banana c = apple
Les fruits ont été triés en ordre alphabétique inverse, et leurs index respectifs ont été conservés.
Voir aussi
- sort() - Trie un tableau en ordre croissant
- asort() - Trie un tableau en ordre croissant et conserve l'association des index
- Les fonctions de tri des tableaux
add a note
User Contributed Notes 6 notes
stephenakins at gmail dot com ¶
7 years ago
morgan at anomalyinc dot com ¶
25 years ago
If you need to sort a multi-demension array, for example, an array such as
$TeamInfo[$TeamID]["WinRecord"]
$TeamInfo[$TeamID]["LossRecord"]
$TeamInfo[$TeamID]["TieRecord"]
$TeamInfo[$TeamID]["GoalDiff"]
$TeamInfo[$TeamID]["TeamPoints"]
and you have say, 100 teams here, and want to sort by "TeamPoints":
first, create your multi-dimensional array. Now, create another, single dimension array populated with the scores from the first array, and with indexes of corresponding team_id... ie
$foo[25] = 14
$foo[47] = 42
or whatever.
Now, asort or arsort the second array.
Since the array is now sorted by score or wins/losses or whatever you put in it, the indices are all hoopajooped.
If you just walk through the array, grabbing the index of each entry, (look at the asort example. that for loop does just that) then the index you get will point right back to one of the values of the multi-dimensional array.
Not sure if that's clear, but mail me if it isn't...
-mo
FatBat ¶
13 years ago
Needed to get the index of the max/highest value in an assoc array.
max() only returned the value, no index, so I did this instead.
<?php
reset($x); // optional.
arsort($x);
$key_of_max = key($x); // returns the index.
?>
rodders_plonker at yahoo dot com ¶
24 years ago
I was having trouble with the arsort() function on an older version of PHP which was returning an error along the lines of 'wrong perameter count for function arsort' when I tried to use a flag for numeric sorting (2/SORT_NUMERIC).
I figured, as I only wanted to sort integers, I could pad numbers from the left to a specific length with 0's (using the lpad function provided by improv@magma.ca in the notes at http://www.php.net/manual/ref.strings.php).
A string sort then correctly sorts numerically (i.e. {30,2,10,21} becomes {030,021,010,002} not {30,21,2,10}) when echoing the number an (int)$string_name hides the leading 0's.
Made my day :).
Rodders.
jordancdarwin at googlemail dot com ¶
17 years ago
A lot of people seem to trip up on this and ask me questions as to debugging. Bear in mind that this returns boolean, and does not return an array of affected items.
$array = array("One"=>1, "Three" => 3,"Two" =>2);
print_r(asort($array));
If successful, will return 1, and error if there is a string used. Useful to note so then people stop asking me :D
sebas2day ¶
12 years ago
If you are dealing with a multidimensional array you want to sort, then this might be helpfull:
<?php
function array_sort($arr){
if(empty($arr)) return $arr;
foreach($arr as $k => $a){
if(!is_array($a)){
arsort($arr); // could be any kind of sort
return $arr;
}else{
$arr[$k] = array_sort($a);
}
}
return $arr;
}
?>
