String comparisons using a "natural order" algorithm

Descrierea

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". Note that this comparison is case sensitive.

Parametri

str1: The first string.
str2: The second string.

Valorile întoarse

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.

Exemple

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);
?>

Exemplul de mai sus va afișa:

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 information see: Martin Pool's » Natural Order String Comparison page.

Vedeți de asemenea

preg_match() - Perform a regular expression match
strcasecmp() - Binary safe case-insensitive string comparison
substr() - Return part of a string
stristr() - Case-insensitive strstr
strcmp() - Binary safe string comparison
strncmp() - Binary safe string comparison of the first n characters
strncasecmp() - Binary safe case-insensitive string comparison of the first n characters
strnatcasecmp() - Case insensitive string comparisons using a "natural order" algorithm
strstr() - Find the first occurrence of a string
natsort() - Sort an array using a "natural order" algorithm
natcasesort() - Sort an array using a case insensitive "natural order" algorithm