natsort

(PHP 4, PHP 5, PHP 7)
Sort an array using a "natural order" algorithm
bool natsort ( array &$array )

This function 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 sort()) can be seen in the example below.

Parameters:
array

The input array.

Returns:

Returns TRUE on success or FALSE on failure.

Changelog:
5.2.10

Zero padded numeric strings (e.g., '00005') now essentially ignore the 0 padding.

Examples:
natsort() examples demonstrating basic usage
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<?php
$array1 $array2 array("img12.png""img10.png""img2.png""img1.png");
 
asort($array1);
echo "Standard sorting\n";
print_r($array1);
 
natsort($array2);
echo "\nNatural order sorting\n";
print_r($array2);
?>

The above example will output:

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

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

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

natsort() examples demonstrating potential gotchas
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<?php
echo "Negative numbers\n";
$negative array('-5','3','-2','0','-1000','9','1');
print_r($negative);
natsort($negative);
print_r($negative);
 
echo "Zero padding\n";
$zeros array('09''8''10''009''011''0'); 
print_r($zeros);
natsort($zeros);
print_r($zeros);
?>

The above example will output:

Negative numbers
Array
(
    [0] => -5
    [1] => 3
    [2] => -2
    [3] => 0
    [4] => -1000
    [5] => 9
    [6] => 1
)
Array
(
    [2] => -2
    [0] => -5
    [4] => -1000
    [3] => 0
    [6] => 1
    [1] => 3
    [5] => 9
)

Zero padding
Array
(
    [0] => 09
    [1] => 8
    [2] => 10
    [3] => 009
    [4] => 011
    [5] => 0
)
Array
(
    [5] => 0
    [1] => 8
    [3] => 009
    [0] => 09
    [2] => 10
    [4] => 011
)
See also:

natcasesort() -

comparison of array sorting functions -

strnatcmp() -

strnatcasecmp() -

doc_php
2025-01-10 15:47:30
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