The function treats '_' as after letters and numbers when it would be placed before logically.
strnatcasecmp
(PHP 4, PHP 5, PHP 7, PHP 8)
strnatcasecmp — Case insensitive string comparisons using a "natural order" algorithm
Description
This function implements a comparison algorithm that orders alphanumeric strings in the way a human being would. The behaviour of this function is similar to strnatcmp(), except that the comparison is not case sensitive. For more information see: Martin Pool's » Natural Order String Comparison page.
Parameters
-
string1 -
The first string.
-
string2 -
The second string.
Return Values
Similar to other string comparison functions, this one returns -1 if
string1 is less than string2
1 if string1 is greater than
string2, and 0 if they are equal.
Changelog
| Version | Description |
|---|---|
| 8.2.0 |
This function now returns -1 or 1,
where it previously returned a negative or positive number.
|
Examples
Example #1 strnatcasecmp() example
<?php
var_dump(strnatcasecmp('Apple', 'Banana'));
var_dump(strnatcasecmp('Banana', 'Apple'));
var_dump(strnatcasecmp('apple', 'Apple'));
?>The above example will output:
int(-1) int(1) int(0)
See Also
- preg_match() - Perform a regular expression match
- strcmp() - Binary safe string comparison
- strcasecmp() - Binary safe case-insensitive string comparison
- substr() - Return part of a string
- stristr() - Case-insensitive strstr
- strncasecmp() - Binary safe case-insensitive string comparison of the first n characters
- strncmp() - Binary safe string comparison of the first n characters
- strstr() - Find the first occurrence of a string
- setlocale() - Set locale information
add a note
User Contributed Notes 3 notes
chatfielddaniel at googlemail dot com ¶
13 years ago
Marco ¶
8 years ago
Use strnatcmp to avoid the _ problem as mentioned below;
<< The function treats '_' as after letters and numbers when it would be placed before logically. >>
thomas at uninet dot se ¶
18 years ago
There seems to be a bug in the localization for strnatcmp and strnatcasecmp. I searched the reported bugs and found a few entries which were up to four years old (but the problem still exists when using swedish characters).
These functions might work instead.
<?php
function _strnatcasecmp($left, $right) {
return _strnatcmp(strtolower($left), strtolower($right));
}
function _strnatcmp($left, $right) {
while((strlen($left) > 0) && (strlen($right) > 0)) {
if(preg_match('/^([^0-9]*)([0-9].*)$/Us', $left, $lMatch)) {
$lTest = $lMatch[1];
$left = $lMatch[2];
} else {
$lTest = $left;
$left = '';
}
if(preg_match('/^([^0-9]*)([0-9].*)$/Us', $right, $rMatch)) {
$rTest = $rMatch[1];
$right = $rMatch[2];
} else {
$rTest = $right;
$right = '';
}
$test = strcmp($lTest, $rTest);
if($test != 0) {
return $test;
}
if(preg_match('/^([0-9]+)([^0-9].*)?$/Us', $left, $lMatch)) {
$lTest = intval($lMatch[1]);
$left = $lMatch[2];
} else {
$lTest = 0;
}
if(preg_match('/^([0-9]+)([^0-9].*)?$/Us', $right, $rMatch)) {
$rTest = intval($rMatch[1]);
$right = $rMatch[2];
} else {
$rTest = 0;
}
$test = $lTest - $rTest;
if($test != 0) {
return $test;
}
}
return strcmp($left, $right);
}
?>
The code is not optimized. It was just made to solve my problem.
