Russian Ukraine English
Catalog RSS


strnatcmp

(PHP 4 >= 4.0RC2)

strnatcmp -- String comparisons using a "natural order" algorithm

Description

int strnatcmp (string str1, string str2)

This function implements a comparison algorithm that orders alphanumeric strings in the way a human being would, this is described as a "natural ordering". An example of the difference between this algorithm and the regular computer string sorting algorithms (used in strcmp()) can be seen below:

$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); 	  

The code above will generate the following 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 ) 	  

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

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.

Note that this comparison is case sensitive.

See also ereg(), strcasecmp(), substr(), stristr(), strcmp(), strncmp(), strncasecmp(), strnatcasecmp(), strstr(), natsort() and natcasesort().

Led