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arsort

(PHP 4, PHP 5, PHP 7, PHP 8)

arsortOrdena um array em ordem descrescente e mantém a associação de índices

Descrição

arsort(array &$array, int $flags = SORT_REGULAR): true

Ordena o array em ordem decrescente, de forma que suas chaves mantenham suas correlações com os valores aos quais estão associadas.

É usada principalmente para ordenar arrays associativos onde a ordem dos elementos é um fator significativo.

Nota:

Se dois elementos são comparados como iguais, eles mantêm sua ordem original. Antes do PHP 8.0.0, sua ordem relativa no array ordenado era indefinida.

Nota:

Redefine o ponteiro interno do array para o primeiro elemento.

Parâmetros

array

O array de entrada.

flags

O segundo parâmetro opcional flags pode ser usado para modificar o comportamento da ordenação usando estes valores:

Flags dos tipos de ordenação:

Valor Retornado

Sempre retorna true.

Registro de Alterações

Versão Descrição
8.2.0 O tipo do retorno agora é true; anteriormente, era bool.

Exemplos

Exemplo #1 Exemplo de arsort()

<?php
$frutas
= array("d" => "limão", "a" => "laranja", "b" => "banana", "c" => "maçã");
arsort($frutas);
foreach (
$frutas as $chave => $valor) {
echo
"$chave = $valor\n";
}
?>

O exemplo acima produzirá:

c = maçã
d = limao
a = laranja
b = banana

As frutas foram ordenadas na ordem alfabética inversa, e os índices associados a cada elemento foram mantidos.

Veja Também

add a note

User Contributed Notes 6 notes

up
12
stephenakins at gmail dot com
6 years ago
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 )
up
13
morgan at anomalyinc dot com
24 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
up
-1
FatBat
12 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.
?>
up
-6
rodders_plonker at yahoo dot com
23 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.
up
-9
jordancdarwin at googlemail dot com
16 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
up
-16
sebas2day
11 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;
}
?>
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