Overview
KB
Technical FAQ
PHP Manual
CSS2 Manual
HTML Manual
JS Guide
JS Reference
PhpDock Manual
Nu-Coder Manual
PhpExpress Manual
PHP Joomla
Development
Learn PHP
 
<ArrayObject::getIteratorClassArrayObject::natcasesort>
^ArrayObjectLast updated: Mon, 26 Oct 2026

ArrayObject::ksort

(PHP 5 >= 5.2.0, PHP 7, PHP 8)

ArrayObject::ksort — Sort the entries by key

Description

public function ArrayObject::ksort(int $flags = SORT_REGULAR): true

Sorts the entries by key, maintaining key to entry correlations. This is useful mainly for associative arrays.

Note:

If two members compare as equal, they retain their original order. Prior to PHP 8.0.0, their relative order in the sorted array was undefined.

Parameters

flags

The optional second parameter flags may be used to modify the sorting behavior using these values:

Sorting type flags:

Return Values

Always returns true.

Changelog

Version Description
8.2.0 The return type is true now; previously, it was bool.

Examples

Example #1 ArrayObject::ksort() example

<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
$fruitArrayObject = new ArrayObject($fruits);
$fruitArrayObject->ksort();

foreach ($fruitArrayObject as $key => $val) {
    echo "$key = $val\n";
}
 ?>

The above example will output:

a = orange
b = banana
c = apple
d = lemon

See Also


<ArrayObject::getIteratorClassArrayObject::natcasesort>
^ArrayObjectLast updated: Mon, 26 Oct 2026