PHP - Manual: natcasesort

2024-12-22

natsort »

« list

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): bool

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 。

范例

示例 #1 natcasesort() 例子


<?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);
?>

以上例程会输出：

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

natsort() - 用“自然排序”算法对数组排序
数组排序函数对比
strnatcmp() - 使用自然排序算法比较字符串
strnatcasecmp() - 使用“自然顺序”算法比较字符串（不区分大小写）

add a note

User Contributed Notes 6 notes

down

dslicer at maine dot rr dot com ¶

19 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);

down

w-dot-rosenbach-at-netskill-de ¶

11 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>';

?>

down

claude at schlesser dot lu ¶

13 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 :)

down

-3

vbAlexDOSMan at Yahoo dot com ¶

18 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));
  }
}

down

-4

tmiller25 at hotmail dot com ¶

20 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;
    }
  }
--------------------

down

-7

shawn at shawnwilkerson dot com ¶

13 years ago


I kept getting varied results using natcasesort and sort on mixed arrays -- per the descriptions.

Sometimes simple is better:

A little snippet of code:

<?php                        if($responders->num_rows) {
                            $i=0;
                            while($row= $responders->fetch_assoc()) {
                                $user=getUserName($row['responderID']);
                                $r[$i]= array("sortname"=>strtolower($user),"userName"=>$user, "userID"=>$row['responderID'], "responderID"=>$row['idresponders']);
                                $i++;
                            }
                            sort($r);
                            print_r($r);                            
                        }

?>

I simply created a lower cased sort field at the front of the result set and then sort by it -- which provides the expected result and leaves the actual needed fields unchanged.

For the curious:  all user information is kept completed in another database (and table) from the content database due to security reasons.  The getUser functions we have written allow us to pull only what is legally allowed without exposing anything else.

This is why a left join or something wasn't used and we have to build a pseudo result array here from both databases.

add a note

官方地址：https://www.php.net/manual/en/function.natcasesort.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络数据库 JAVA 面试 NoSQL C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 adodb手册 ADORecordSet对象 opcache预加载 Composer的Packagist资源 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet PHP json解析（json_decode）页面工具 mysql面试题 [原创]诡异的php-fpm超时问题 php中几种注释规范纯php实现DES以及TripleDES加密算法 php 修改图片大小支持php7的性能采集扩展 [鸟哥]PHP FFI详解 - 一种全新的PHP扩展方式

略微加速

PHP官方手册 - 互联网笔记

natcasesort

说明

参数

返回值

范例

参见

User Contributed Notes 6 notes