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strnatcasecmp

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

strnatcasecmp — 使用“自然顺序”算法比较字符串（不区分大小写）

说明

strnatcasecmp(string $string1, string $string2): int

该函数实现了以人类习惯对数字型字符串进行排序的比较算法。除了不区分大小写，该函数的行为与 strnatcmp() 类似。更多信息，参见：Martin Pool 的» 自然顺序的字符串比较页面。

参数

string1: 第一个字符串。
string2: 第二个字符串。

返回值

与其他字符串比较函数类似，如果 string1 小于 string2 返回 -1；如果 string1 大于 string2 返回 1；如果两者相等，返回 0。

更新日志

版本	说明
8.2.0	现在此函数返回 `-1` 或者 `1`，之前返回负数或正数。

示例

示例 #1 strnatcasecmp() 示例

<?php

var_dump(strnatcasecmp('Apple', 'Banana'));
var_dump(strnatcasecmp('Banana', 'Apple'));
var_dump(strnatcasecmp('apple', 'Apple'));
?>

以上示例会输出：

 
int(-1)
int(1)
int(0)

参见

preg_match() - 执行匹配正则表达式
strcmp() - 二进制安全字符串比较
strcasecmp() - 二进制安全比较字符串（不区分大小写）
substr() - 返回字符串的子串
stristr() - strstr 函数的忽略大小写版本
strncasecmp() - 二进制安全比较字符串开头的若干个字符（不区分大小写）
strncmp() - 二进制安全比较字符串开头的若干个字符
strstr() - 查找字符串的首次出现
setlocale() - 设置区域信息

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User Contributed Notes 3 notes

down

chatfielddaniel at googlemail dot com ¶

12 years ago

The function treats '_' as after letters and numbers when it would be placed before logically.

down

Marco ¶

7 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. >>

down

-17

thomas at uninet dot se ¶

17 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.

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