Using natcasesort() for Case‑Insensitive Natural Order Sorting in PHP

The natcasesort() function in PHP is the case‑insensitive version of natsort(), implementing a natural order sorting algorithm that keeps the original keys associated with their values.

Parameters array &$array – the input array to be sorted.

Return value

Returns TRUE on success, or FALSE on failure.

Example

The following code demonstrates standard sorting with sort() and natural order case‑insensitive sorting with natcasesort():

<?php
$array1 = $array2 = array(
    'IMG0.png',
    'img12.png',
    'img10.png',
    'img2.png',
    'IMG3.png'
);

sort($array1);
echo "Standard sorting
";
print_r($array1);

natcasesort($array2);
echo "
Natural order sorting (case‑insensitive)
";
print_r($array2);
?>

Output

Standard sorting
Array
(
    [0] => IMG0.png
    [1] => IMG3.png
    [2] => img1.png
    [3] => img10.png
    [4] => img12.png
)

Natural order sorting (case‑insensitive)
Array
(
    [0] => IMG0.png
    [1] => IMG3.png
    [2] => img1.png
    [3] => img10.png
    [4] => img12.png
)