uasort

(PHP 4, PHP 5, PHP 7)

uasortSort an array with a user-defined comparison function and maintain index association

Descrierea

uasort ( array &$array , callable $callback ) : bool

This function sorts an array such that array indices maintain their correlation with the array elements they are associated with, using a user-defined comparison function.

This is used mainly when sorting associative arrays where the actual element order is significant.

Notă:

Dacă în rezultatul comparației doi membri sunt egali, ordinea lor relativă în tabloul sortat nu este definită.

Parametri

array

The input array.

callback

See usort() and uksort() for examples of user-defined comparison functions.

Valorile întoarse

Întoarce valoarea true în cazul succesului sau false în cazul eșecului.

Exemple

Example #1 Basic uasort() example

<?php
// Comparison function
function cmp($a$b) {
    if (
$a == $b) {
        return 
0;
    }
    return (
$a $b) ? -1;
}

// Array to be sorted
$array = array('a' => 4'b' => 8'c' => -1'd' => -9'e' => 2'f' => 5'g' => 3'h' => -4);
print_r($array);

// Sort and print the resulting array
uasort($array'cmp');
print_r($array);
?>

Exemplul de mai sus va afișa:

Array
(
    [a] => 4
    [b] => 8
    [c] => -1
    [d] => -9
    [e] => 2
    [f] => 5
    [g] => 3
    [h] => -4
)
Array
(
    [d] => -9
    [h] => -4
    [c] => -1
    [e] => 2
    [g] => 3
    [a] => 4
    [f] => 5
    [b] => 8
)

A se vedea și

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User Contributed Notes 3 notes

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153
magikMaker
14 years ago
a quick reminder on the syntax if you want to use uasort in a Class or Object:

<?php

// procedural:
uasort($collection, 'my_sort_function');

// Object Oriented
uasort($collection, array($this, 'mySortMethod'));

// Objet Oriented with static method
uasort($collection, array('self', 'myStaticSortMethod'));

?>
up
32
yannick dot battail at gmail dot com
14 years ago
An Example using anonymous function.
Anonymous functions make some time the code easier to understand.
<?php
$fruits
= array('Orange9','Orange11','Orange10','Orange6','Orange15');
uasort ( $fruits , function ($a, $b) {
            return
strnatcmp($a,$b); // or other function/code
       
}
    );
print_r($fruits);
?>
returns
Array
(
    [3] => Orange6
    [0] => Orange9
    [2] => Orange10
    [1] => Orange11
    [4] => Orange15
)
up
2
php at eden2 dot com
21 years ago
Is it just me, or are the examples below misleading, and actually demonstrating situations that would be more appropriate for usort()?

After trying to make sense of the uasort() description, it sounds like it's more for sorting a 1D array like this:

"john" => "$23.12"
"tim" => "$6.50"
"bob" => "$18.54"

and getting back:

"tim" => "$6.50"
"bob" => "$18.54"
"john" => $23.12"

(assuming, of course, that your sort function is lopping off the $ and evaluating as a number -- which would complicate the use of asort() ;)
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