(PHP 4, PHP 5)
strnatcmp — String comparisons using a "natural order" algorithm
This function implements a comparison algorithm that orders alphanumeric strings in the way a human being would, this is described as a "natural ordering". Note that this comparison is case sensitive.
The first string.
The second string.
Similar to other string comparison functions, this one returns < 0 if str1 is less than str2 ; > 0 if str1 is greater than str2 , and 0 if they are equal.
An example of the difference between this algorithm and the regular computer string sorting algorithms (used in strcmp()) can be seen below:
<?php
$arr1 = $arr2 = array("img12.png", "img10.png", "img2.png", "img1.png");
echo "Standard string comparison\n";
usort($arr1, "strcmp");
print_r($arr1);
echo "\nNatural order string comparison\n";
usort($arr2, "strnatcmp");
print_r($arr2);
?>
上例将输出：
Standard string comparison Array ( [0] => img1.png [1] => img10.png [2] => img12.png [3] => img2.png ) Natural order string comparison Array ( [0] => img1.png [1] => img2.png [2] => img10.png [3] => img12.png )