在 PHP 中将字符串拆分为 Unicode 字符数组的最佳方法是什么? [英] What is the best way to split a string into an array of Unicode characters in PHP?

问题描述

在 PHP 中，将字符串拆分为 Unicode 字符数组的最佳方法是什么?如果输入的不一定是UTF-8?

In PHP, what is the best way to split a string into an array of Unicode characters? If the input is not necessarily UTF-8?

我想知道输入字符串中的 Unicode 字符集是否是另一组 Unicode 字符的子集.

I want to know whether the set of Unicode characters in an input string is a subset of another set of Unicode characters.

为什么不直接运行 mb_ 函数系列，因为前几个答案没有?

Why not run straight for the mb_ family of functions, as the first couple of answers didn't?

推荐答案

您可以在 PCRE 正则表达式中使用 'u' 修饰符；请参阅模式修饰符(引用):

You could use the 'u' modifier with PCRE regex ; see Pattern Modifiers (quoting) :

你(PCRE8)

这个修饰符开启额外的PCRE 的功能是与 Perl 不兼容.图案字符串被视为 UTF-8.这个修饰符可从 PHP 4.1.0 获得Unix 或更高版本和 PHP 4.2.3在 win32 上.UTF-8 的有效性自 PHP 4.3.5 起检查模式.

This modifier turns on additional functionality of PCRE that is incompatible with Perl. Pattern strings are treated as UTF-8. This modifier is available from PHP 4.1.0 or greater on Unix and from PHP 4.2.3 on win32. UTF-8 validity of the pattern is checked since PHP 4.3.5.

例如，考虑这个代码:

header('Content-type: text/html; charset=UTF-8');  // So the browser doesn't make our lives harder
$str = "abc 文字化け, efg";

$results = array();
preg_match_all('/./', $str, $results);
var_dump($results[0]);

你会得到一个无法使用的结果:

You'll get an unusable result:

array
  0 => string 'a' (length=1)
  1 => string 'b' (length=1)
  2 => string 'c' (length=1)
  3 => string ' ' (length=1)
  4 => string '�' (length=1)
  5 => string '�' (length=1)
  6 => string '�' (length=1)
  7 => string '�' (length=1)
  8 => string '�' (length=1)
  9 => string '�' (length=1)
  10 => string '�' (length=1)
  11 => string '�' (length=1)
  12 => string '�' (length=1)
  13 => string '�' (length=1)
  14 => string '�' (length=1)
  15 => string '�' (length=1)
  16 => string ',' (length=1)
  17 => string ' ' (length=1)
  18 => string 'e' (length=1)
  19 => string 'f' (length=1)
  20 => string 'g' (length=1)

但是，使用此代码:

header('Content-type: text/html; charset=UTF-8');  // So the browser doesn't make our lives harder
$str = "abc 文字化け, efg";

$results = array();
preg_match_all('/./u', $str, $results);
var_dump($results[0]);

(注意正则表达式末尾的u")

你得到你想要的:

array
  0 => string 'a' (length=1)
  1 => string 'b' (length=1)
  2 => string 'c' (length=1)
  3 => string ' ' (length=1)
  4 => string '文' (length=3)
  5 => string '字' (length=3)
  6 => string '化' (length=3)
  7 => string 'け' (length=3)
  8 => string ',' (length=1)
  9 => string ' ' (length=1)
  10 => string 'e' (length=1)
  11 => string 'f' (length=1)
  12 => string 'g' (length=1)

希望这有帮助:-)

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