PHP Manual
ArrayObject
Sort entries using a "natural order" algorithm

ArrayObject::natsort

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

ArrayObject::natsort — Sort entries using a "natural order" algorithm

Description

public ArrayObject::natsort(): bool

This method implements a sort algorithm that orders alphanumeric strings in the way a human being would while maintaining key/value associations. This is described as a "natural ordering". An example of the difference between this algorithm and the regular computer string sorting algorithms (used in ArrayObject::asort) method can be seen in the example below.

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

This function has no parameters.

Return Values

No value is returned.

Examples

Example #1 ArrayObject::natsort() example


<?php
$array = array("img12.png", "img10.png", "img2.png", "img1.png");

$arr1 = new ArrayObject($array);
$arr2 = clone $arr1;

$arr1->asort();
echo "Standard sorting\n";
print_r($arr1);

$arr2->natsort();
echo "\nNatural order sorting\n";
print_r($arr2);
?>

The above example will output:

Standard sorting
ArrayObject Object
(
    [3] => img1.png
    [1] => img10.png
    [0] => img12.png
    [2] => img2.png
)

Natural order sorting
ArrayObject Object
(
    [3] => img1.png
    [2] => img2.png
    [1] => img10.png
    [0] => img12.png
)

For more information see: Martin Pool's » Natural Order String Comparison page.