strnatcmp String comparisons using a "natural order" algorithm intstrnatcmp stringstr1 stringstr2 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: ]]> The code above will generate the following output: 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 information 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 preg_match, strcasecmp, substr, stristr, strcmp, strncmp, strncasecmp, strnatcasecmp, strstr, natsort and natcasesort.