STRNATCMP(3) 1 STRNATCMP(3)
strnatcmp - String comparisons using a ";natural order" algorithm
SYNOPSIS
int strnatcmp (string $str1, string $str2)
DESCRIPTION
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.
PARAMETERS
o $str1
- The first string.
o $str2
- The second string.
RETURN VALUES
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.
EXAMPLES
An example of the difference between this algorithm and the regular computer string sorting algorithms (used in strcmp(3)) can be seen
below:
<?php
$arr1 = $arr2 = array("img12.png", "img10.png", "img2.png", "img1.png");
echo "Standard string comparison
";
usort($arr1, "strcmp");
print_r($arr1);
echo "
Natural order string comparison
";
usort($arr2, "strnatcmp");
print_r($arr2);
?>
The above example will output:
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
)
SEE ALSO
preg_match(3), strcasecmp(3), substr(3), stristr(3), strcmp(3), strncmp(3), strncasecmp(3), strnatcasecmp(3), strstr(3), natsort(3), nat-
casesort(3).
PHP Documentation Group STRNATCMP(3)