PHP 8.4.1 Released!

    natcasesort

    (PHP 4, PHP 5, PHP 7, PHP 8)

    natcasesort — 用“自然排序”算法对数组进行不区分大小写字母的排序

    说明

    natcasesort(array &$array): true

    natcasesort() 是 natsort() 函数的不区分大小写字母的版本。

    本函数实现了一个和人们通常对字母数字字符串进行排序的方法一样的排序算法并保持原有键／值的关联，这被称为“自然排序”。

    注意:

    如果两个成员完全相同，那么它们将保持原来的顺序。 在 PHP 8.0.0 之前，它们在排序数组中的相对顺序是未定义的。

    注意:

    重置数组中的内部指针，指向第一个元素。

    参数

    array

    输入的数组。

    返回值

    总是返回 true。

    更新日志

    版本 说明
    8.2.0 现在返回类型为 true；之前是 bool。

    示例

    示例 #1 natcasesort() 示例

    <?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);
    ?>

    以上示例会输出：

    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
)

    更多信息见 Martin Pool 的 » Natural Order String Comparison 页面。

    参见

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    用户贡献的备注 5 notes

    up
    44
    dslicer at maine dot rr dot com
    21 years ago
    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);
    up
    3
    w-dot-rosenbach-at-netskill-de
    13 years ago
    Sorting UTF-8 by arbitrary order:

    <?php
    mb_internal_encoding    ("UTF-8");

    class     utf_8_german
    {
    // everything else is sorted at the end
    static $order = '0123456789AaÄäBbCcDdEeFfGgHhIiJjKkLlMm
    NnOoÖöPpQqRrSsßTtUuÜüVvWwXxYyZz'    ;
    static     $char2order;

    static function     cmp($a, $b) {
    if (    $a == $b) {
    return     0;
    }

    // lazy init mapping
    if (empty(self::$char2order))
    {
    $order = 1;
    $len = mb_strlen(self::$order);
    for (    $order=0; $order<$len; ++$order)
    {
    self::$char2order[mb_substr(self::$order, $order, 1)] = $order;
    }
    }

    $len_a = mb_strlen($a);
    $len_b = mb_strlen($b);
    $max=min($len_a, $len_b);
    for(    $i=0; $i<$max; ++$i)
    {
    $char_a= mb_substr($a, $i, 1);
    $char_b= mb_substr($b, $i, 1);

    if (    $char_a == $char_b) continue;
    $order_a = (isset(self::$char2order[$char_a])) ? self::$char2order[$char_a] : 9999;
    $order_b = (isset(self::$char2order[$char_b])) ? self::$char2order[$char_b] : 9999;

    return (    $order_a < $order_b) ? -1 : 1;
    }
    return (    $len_a < $len_b) ? -1 : 1;
    }
    }

    // usage example:

    $t = array(
    'Birnen', 'Birne', 'Äpfel', 'Apfel',
    );

    uasort($t, 'utf_8_german::cmp');
    echo     '$t: <pre>'.htmlspecialchars(print_r($t,true),null,'UTF-8').'</pre>';
    ?>
    up
    -1
    claude at schlesser dot lu
    15 years ago
    Here a function that will natural sort an array by keys with keys that contain special characters.

    <?php
    function natksort($array)
    {
    $original_keys_arr = array();
    $original_values_arr = array();
    $clean_keys_arr = array();

    $i = 0;
    foreach (    $array AS $key => $value)
    {
    $original_keys_arr[$i] = $key;
    $original_values_arr[$i] = $value;
    $clean_keys_arr[$i] = strtr($key, "ÄÖÜäöüÉÈÀËëéèàç", "AOUaouEEAEeeeac");
    $i++;
    }

    natcasesort($clean_keys_arr);

    $result_arr = array();

    foreach (    $clean_keys_arr AS $key => $value)
    {
    $original_key = $original_keys_arr[$key];
    $original_value = $original_values_arr[$key];
    $result_arr[$original_key] = $original_value;
    }

    return     $result_arr;
    }
    ?>

    Hope it will be useful to somebody :)
    up
    -1
    vbAlexDOSMan at Yahoo dot com
    21 years ago
    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($this));
    }
    }
    up
    -5
    tmiller25 at hotmail dot com
    22 years ago
    add this loop to the function above if you want items which have the same first characters to be listed in a way that the shorter string comes first.
    --------------------
    /* short before longer (e.g. 'abc' should come before 'abcd') */
    for($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;
    }
    }
    --------------------
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