ArrayObject::uksort

(PHP 5 >= 5.2.0)

ArrayObject::uksort — Sort the entries by keys using a user-defined comparison function

Description

void ArrayObject::uksort ( callback $cmp_function )

This function sorts the keys of the entries using a user-supplied comparison function. The key to entry correlations will be maintained.

Parameters

cmp_function

The callback comparison function.

Function cmp_function should accept two parameters which will be filled by pairs of entry keys. The comparison function must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.

Return Values

No value is returned.

Examples

Example #1 ArrayObject::uksort() example

<?php
function cmp($a, $b) {
    $a = preg_replace('@^(a|an|the) @', '', $a);
    $b = preg_replace('@^(a|an|the) @', '', $b);
    return strcasecmp($a, $b);
}

$array = array("John" => 1, "the Earth" => 2, "an apple" => 3, "a banana" => 4);
$arrayObject = new ArrayObject($array);
$arrayObject->uksort('cmp');

foreach ($arrayObject as $key => $value) {
    echo "$key: $value\n";
}
?>

The above example will output:

an apple: 3
a banana: 4
the Earth: 2
John: 1