strnatcasecmp()

(PHP 4, PHP 5, PHP 7)

使用“自然顺序”算法比较字符串（不区分大小写）

说明

strnatcasecmp(string $str1, string $str2) : 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

$str1

第一个字符串。

$str2

第二个字符串。

返回值

与其他字符串比较函数类似，如果$str1小于$str2返回< 0；如果$str1大于$str2返回> 0；如果两者相等，返回 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()设置地区信息

Use strnatcmp to avoid the _ problem as mentioned below;
<< The function treats '_' as after letters and numbers when it would be placed before logically. >>

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

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.