natcasesort

Sort an array using a case insensitive "natural order" algorithm (PHP 4, PHP 5)
bool natcasesort ( array &array )

This function implements a sort algorithm that orders alphanumeric strings in the way a human being would while maintaining key/value associations. This is described as a "natural ordering".

Returns TRUE on success or FALSE on failure.

natcasesort() is a case insensitive version of natsort().

Example 315. natcasesort() example

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<?php

$array1 = $array2 = array('IMG0.png', 'img12.png', 'img10.png', 'img2.png', 'img1.png', 'IMG3.png');

sort($array1);

echo "Standard sorting\n";
print_r($array1);

natcasesort($array2);

echo "\nNatural order sorting (case-insensitive)\n";
print_r($array2);
?>

The above example will output:

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Standard sorting

Array

(

    [0] => IMG0.png

    [1] => IMG3.png

    [2] => img1.png

    [3] => img10.png

    [4] => img12.png

    [5] => img2.png

)


Natural order sorting (case-insensitive)

Array

(

    [0] => IMG0.png

    [4] => img1.png

    [3] => img2.png

    [5] => IMG3.png

    [2] => img10.png

    [1] => img12.png

)

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

Code Examples / Notes » natcasesort

Ulli at Stemmeler dot net: I remade your function -- it's a little more compact now -- Enjoy... function ignorecasesort(&$array) { /*Make each element it's lowercase self plus itself*/ /*(e.g. "MyWebSite" would become "mywebsiteMyWebSite"*/ for ($i = 0; $i < sizeof($array); $array[$i] = strtolower($array[$i]).$array[$i], $i++); /*Sort it -- only the lowercase versions will be used*/ sort($array); /*Take each array element, cut it in half, and add the latter half to a new array*/ /*(e.g. "mywebsiteMyWebSite" would become "MyWebSite")*/ for ($i = 0; $i < sizeof($array); $i++) { $this = $array[$i]; $array[$i] = substr($this, (strlen($this)/2), strlen($this)); } }

Something that should probably be documented is the fact that both natsort and natcasesort maintain the key-value associations of the array. If you natsort a numerically indexed array, a for loop will not produce the sorted order; a foreach loop, however, will produce the sorted order, but the indices won't be in numeric order. If you want natsort and natcasesort to break the key-value associations, just use array_values on the sorted array, like so: natcasesort($arr); $arr = array_values($arr);

natcasesort didn't work first time I needed something like this. Not on my local server, not on my server on the web. I needed an array sorted ignoring upper and lower cases. In the end lower case array-members stayed at the end of the array. I replaced it with this function: --------- function ignorecasesort(&$array) { $separator="|<>|"; for($i=0;$i<sizeof($array);$i++) { $array[$i]=strtolower($array[$i]).$separator.$array[$i]; } sort($array); for($i=0;$i<sizeof($array);$i++) { $this=$array[$i]; $this=explode($separator,$this); $array[$i]=$this[1]; } } ---------

hi all, this is my first post at php.net first of all thank you for this huge site :) ok i found it usefull to post this for others. in the german language we have words like 'ä ö ü' its called "umlaute" and it was a problem to me to "naturally" sort an huge array correctly so i coded this small block to get me helped, if anyone has an better idea please post and let us know as i am not a real crack :) 1. change each "umlaut" (äöüß) into its "nearest" equivalent 2. natcasesorting it naturally 3. re-assiging the correct sorted array with the original-words again while keeping track of the KEY... example-array: $aSupplier = array(3 => "MAN",2 => "Atlas",16 => "Chevrolet",17 => "Chrysler",19 => "Citroen",24 => "DAF",25 => "Daihatsu",27 => "Daewoo",28 => "Demag",30 => "Dodge",36 => "Schierling",208 => "HIAB",38 => "Hüffermann",39 => "Gergen",40 => "Kubato",41 => "Faun",43 => "Kleindienst",44 => "Swing",45 => "Neuhaus",46 => "Unimog",47 => "Meiller",48 => "Pfau-Johnston",49 => "Geesink",50 => "Schörling",51 => "Demag-Witting",53 => "Helmers",54 => "Ellermann",55 => "Jacobsen",56 => "Biki",57 => "Hansa",58 => "Kramer",59 => "Schmitz",60 => "Toro",61 => "Iseki",62 => "Haller",63 => "Kuka",64 => "Brock",65 => "Ambross",66 => "Sobernheimer",67 => "Pietsch",68 => "Küpper",69 => "Weisser",71 => "Wackenhut"); foreach ( $aSupplier as $key => $value ) { $aSupplier2[$key] = strtr($aSupplier[$key], "ÄÖÜäöüß", "AOUaous"); } natcasesort($aSupplier2); foreach ( $aSupplier2 as $key => $value ) { if ( $aSupplier2[$key] != "" ) $aSupplier3[$key] = $aSupplier[$key]; } echo "<pre>"; print_r($aSupplier3); echo "</pre>"; greetz tim

add this loop to the function above if you want items which have the same first characters to be listed in a way that the shorter string comes first. -------------------- /* short before longer (e.g. 'abc' should come before 'abcd') */ for($i=count($array)-1;$i>0;$i--) { $str_a = $array[$i ]; $str_b = $array[$i-1]; $cmp_a = strtolower(substr($str_a,0,strlen($str_a))); $cmp_b = strtolower(substr($str_b,0,strlen($str_a))); if ($cmp_a==$cmp_b && strlen($str_a)<strlen($str_b)) { $array[$i]=$str_b; $array[$i-1]=$str_a; $i+=2; } } --------------------

natcasesort

Sort an array using a case insensitive "natural order" algorithm (PHP 4, PHP 5) bool natcasesort ( array &array )

Example 315. natcasesort() example

Code Examples / Notes » natcasesort

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Sort an array using a case insensitive "natural order" algorithm (PHP 4, PHP 5)
bool natcasesort ( array &array )