如何将特殊字符替换为它们在 PHP 中所基于的字符？答案

【问题标题】：how to replace special characters with the ones they're based on in PHP?如何将特殊字符替换为它们在 PHP 中所基于的字符？
【发布时间】：2010-12-25 20:09:23
【问题描述】：

如何替换：

“ã”与“a”
“é”与“e”

在 PHP 中？这可能吗？我在某处读过，我可以用基本字符的 ascii 值和重音的 ascii 值做一些数学运算，但我现在找不到任何参考。

【问题讨论】：

标签： php string replace special-characters character-encoding

【解决方案1】：

如果您无权访问 Normalizer 类或者只是不想使用它，您可以使用以下函数来替换大多数（全部？）常见的重音。

function Unaccent($string)
{
    return preg_replace('~&([a-z]{1,2})(acute|cedil|circ|grave|lig|orn|ring|slash|th|tilde|uml);~i', '$1', htmlentities($string, ENT_QUOTES, 'UTF-8'));
}

【讨论】：

未捕获的引用错误：未定义 ENT_QUOTES
@SimonArnold：检查您的代码中的& 符号，或者直接复制+粘贴。
当使用它时，它会在包含单个字符（如急性等）时删除所有文本。
它实际上不适用于尖锐的口音（例如尝试“ćwiek”）
@KonradMorawski：确实，我的解决方案并没有处理en.wikipedia.org/wiki/Latin-derived_alphabet 中的所有字符。从那以后，我做了一些补充，但单独使用 htmlentities 并不能开箱即用 - 主要是因为 htmlentities 在编码时不会返回&cacute;。我了解您的需求，只是指出它适用于一些/常见的急性字符。

【解决方案2】：

这个答案不正确。我写的时候不理解 Unicode 规范化。查看 francadaval 的评论和链接

查看 Normalizer 类以执行此操作。文档很好，所以我只是链接它而不是在这里重复：

http://www.php.net/manual/en/class.normalizer.php

具体来说，该类的规范化成员：

http://www.php.net/manual/en/normalizer.normalize.php

请注意，Unicode 规范化有多种形式，您似乎需要规范化形式 KD (NFKD) 兼容性分解，但您应该阅读文档以确保。

您不应该为此尝试推出自己的函数：有太多事情可能出错，使用提供的函数是一个更好的主意。

【讨论】：

这实际上是最干净（也是最有效）的方式，因为它不需要自己管理任何功能（更不用说随身携带不必要的物品了）
同意，很高兴 PHP 终于引入了这个功能。
你确定这行得通吗？ normalizer_normalize('olá', Normalizer::FORM_KD); // olaÌ 我还尝试了所有其他可用的表单，但似乎没有一个只返回 ola。
这样不行。看看我自己对this question的回答。
消除重音（和类似的）不是 Normalizer 的目的。

【解决方案3】：

对于那些没有 php 5.3 的人，我找到了另一个效果很好并且看起来很全面的解决方案。这是作者网站http://www.evaisse.net/2008/php-translit-remove-accent-unaccent-21001的链接。这是函数。

/**
 * Unaccent the input string string. An example string like `ÀØėÿᾜὨζὅБю`
 * will be translated to `AOeyIOzoBY`. More complete than :
 *   strtr( (string)$str,
 *          "ÀÁÂÃÄÅàáâãäåÒÓÔÕÖØòóôõöøÈÉÊËèéêëÇçÌÍÎÏìíîïÙÚÛÜùúûüÿÑñ",
 *          "aaaaaaaaaaaaooooooooooooeeeeeeeecciiiiiiiiuuuuuuuuynn" );
 *
 * @param $str input string
 * @param $utf8 if null, function will detect input string encoding
 * @author http://www.evaisse.net/2008/php-translit-remove-accent-unaccent-21001
 * @return string input string without accent
 */
function remove_accents( $str, $utf8=true )
{
    $str = (string)$str;
    if( is_null($utf8) ) {
        if( !function_exists('mb_detect_encoding') ) {
            $utf8 = (strtolower( mb_detect_encoding($str) )=='utf-8');
        } else {
            $length = strlen($str);
            $utf8 = true;
            for ($i=0; $i < $length; $i++) {
                $c = ord($str[$i]);
                if ($c < 0x80) $n = 0; # 0bbbbbbb
                elseif (($c & 0xE0) == 0xC0) $n=1; # 110bbbbb
                elseif (($c & 0xF0) == 0xE0) $n=2; # 1110bbbb
                elseif (($c & 0xF8) == 0xF0) $n=3; # 11110bbb
                elseif (($c & 0xFC) == 0xF8) $n=4; # 111110bb
                elseif (($c & 0xFE) == 0xFC) $n=5; # 1111110b
                else return false; # Does not match any model
                for ($j=0; $j<$n; $j++) { # n bytes matching 10bbbbbb follow ?
                    if ((++$i == $length)
                        || ((ord($str[$i]) & 0xC0) != 0x80)) {
                        $utf8 = false;
                        break;
                    }

                }
            }
        }

    }

    if(!$utf8)
        $str = utf8_encode($str);

    $transliteration = array(
    'Ĳ' => 'I', 'Ö' => 'O','Œ' => 'O','Ü' => 'U','ä' => 'a','æ' => 'a',
    'ĳ' => 'i','ö' => 'o','œ' => 'o','ü' => 'u','ß' => 's','ſ' => 's',
    'À' => 'A','Á' => 'A','Â' => 'A','Ã' => 'A','Ä' => 'A','Å' => 'A',
    'Æ' => 'A','Ā' => 'A','Ą' => 'A','Ă' => 'A','Ç' => 'C','Ć' => 'C',
    'Č' => 'C','Ĉ' => 'C','Ċ' => 'C','Ď' => 'D','Đ' => 'D','È' => 'E',
    'É' => 'E','Ê' => 'E','Ë' => 'E','Ē' => 'E','Ę' => 'E','Ě' => 'E',
    'Ĕ' => 'E','Ė' => 'E','Ĝ' => 'G','Ğ' => 'G','Ġ' => 'G','Ģ' => 'G',
    'Ĥ' => 'H','Ħ' => 'H','Ì' => 'I','Í' => 'I','Î' => 'I','Ï' => 'I',
    'Ī' => 'I','Ĩ' => 'I','Ĭ' => 'I','Į' => 'I','İ' => 'I','Ĵ' => 'J',
    'Ķ' => 'K','Ľ' => 'K','Ĺ' => 'K','Ļ' => 'K','Ŀ' => 'K','Ł' => 'L',
    'Ñ' => 'N','Ń' => 'N','Ň' => 'N','Ņ' => 'N','Ŋ' => 'N','Ò' => 'O',
    'Ó' => 'O','Ô' => 'O','Õ' => 'O','Ø' => 'O','Ō' => 'O','Ő' => 'O',
    'Ŏ' => 'O','Ŕ' => 'R','Ř' => 'R','Ŗ' => 'R','Ś' => 'S','Ş' => 'S',
    'Ŝ' => 'S','Ș' => 'S','Š' => 'S','Ť' => 'T','Ţ' => 'T','Ŧ' => 'T',
    'Ț' => 'T','Ù' => 'U','Ú' => 'U','Û' => 'U','Ū' => 'U','Ů' => 'U',
    'Ű' => 'U','Ŭ' => 'U','Ũ' => 'U','Ų' => 'U','Ŵ' => 'W','Ŷ' => 'Y',
    'Ÿ' => 'Y','Ý' => 'Y','Ź' => 'Z','Ż' => 'Z','Ž' => 'Z','à' => 'a',
    'á' => 'a','â' => 'a','ã' => 'a','ā' => 'a','ą' => 'a','ă' => 'a',
    'å' => 'a','ç' => 'c','ć' => 'c','č' => 'c','ĉ' => 'c','ċ' => 'c',
    'ď' => 'd','đ' => 'd','è' => 'e','é' => 'e','ê' => 'e','ë' => 'e',
    'ē' => 'e','ę' => 'e','ě' => 'e','ĕ' => 'e','ė' => 'e','ƒ' => 'f',
    'ĝ' => 'g','ğ' => 'g','ġ' => 'g','ģ' => 'g','ĥ' => 'h','ħ' => 'h',
    'ì' => 'i','í' => 'i','î' => 'i','ï' => 'i','ī' => 'i','ĩ' => 'i',
    'ĭ' => 'i','į' => 'i','ı' => 'i','ĵ' => 'j','ķ' => 'k','ĸ' => 'k',
    'ł' => 'l','ľ' => 'l','ĺ' => 'l','ļ' => 'l','ŀ' => 'l','ñ' => 'n',
    'ń' => 'n','ň' => 'n','ņ' => 'n','ŉ' => 'n','ŋ' => 'n','ò' => 'o',
    'ó' => 'o','ô' => 'o','õ' => 'o','ø' => 'o','ō' => 'o','ő' => 'o',
    'ŏ' => 'o','ŕ' => 'r','ř' => 'r','ŗ' => 'r','ś' => 's','š' => 's',
    'ť' => 't','ù' => 'u','ú' => 'u','û' => 'u','ū' => 'u','ů' => 'u',
    'ű' => 'u','ŭ' => 'u','ũ' => 'u','ų' => 'u','ŵ' => 'w','ÿ' => 'y',
    'ý' => 'y','ŷ' => 'y','ż' => 'z','ź' => 'z','ž' => 'z','Α' => 'A',
    'Ά' => 'A','Ἀ' => 'A','Ἁ' => 'A','Ἂ' => 'A','Ἃ' => 'A','Ἄ' => 'A',
    'Ἅ' => 'A','Ἆ' => 'A','Ἇ' => 'A','ᾈ' => 'A','ᾉ' => 'A','ᾊ' => 'A',
    'ᾋ' => 'A','ᾌ' => 'A','ᾍ' => 'A','ᾎ' => 'A','ᾏ' => 'A','Ᾰ' => 'A',
    'Ᾱ' => 'A','Ὰ' => 'A','ᾼ' => 'A','Β' => 'B','Γ' => 'G','Δ' => 'D',
    'Ε' => 'E','Έ' => 'E','Ἐ' => 'E','Ἑ' => 'E','Ἒ' => 'E','Ἓ' => 'E',
    'Ἔ' => 'E','Ἕ' => 'E','Ὲ' => 'E','Ζ' => 'Z','Η' => 'I','Ή' => 'I',
    'Ἠ' => 'I','Ἡ' => 'I','Ἢ' => 'I','Ἣ' => 'I','Ἤ' => 'I','Ἥ' => 'I',
    'Ἦ' => 'I','Ἧ' => 'I','ᾘ' => 'I','ᾙ' => 'I','ᾚ' => 'I','ᾛ' => 'I',
    'ᾜ' => 'I','ᾝ' => 'I','ᾞ' => 'I','ᾟ' => 'I','Ὴ' => 'I','ῌ' => 'I',
    'Θ' => 'T','Ι' => 'I','Ί' => 'I','Ϊ' => 'I','Ἰ' => 'I','Ἱ' => 'I',
    'Ἲ' => 'I','Ἳ' => 'I','Ἴ' => 'I','Ἵ' => 'I','Ἶ' => 'I','Ἷ' => 'I',
    'Ῐ' => 'I','Ῑ' => 'I','Ὶ' => 'I','Κ' => 'K','Λ' => 'L','Μ' => 'M',
    'Ν' => 'N','Ξ' => 'K','Ο' => 'O','Ό' => 'O','Ὀ' => 'O','Ὁ' => 'O',
    'Ὂ' => 'O','Ὃ' => 'O','Ὄ' => 'O','Ὅ' => 'O','Ὸ' => 'O','Π' => 'P',
    'Ρ' => 'R','Ῥ' => 'R','Σ' => 'S','Τ' => 'T','Υ' => 'Y','Ύ' => 'Y',
    'Ϋ' => 'Y','Ὑ' => 'Y','Ὓ' => 'Y','Ὕ' => 'Y','Ὗ' => 'Y','Ῠ' => 'Y',
    'Ῡ' => 'Y','Ὺ' => 'Y','Φ' => 'F','Χ' => 'X','Ψ' => 'P','Ω' => 'O',
    'Ώ' => 'O','Ὠ' => 'O','Ὡ' => 'O','Ὢ' => 'O','Ὣ' => 'O','Ὤ' => 'O',
    'Ὥ' => 'O','Ὦ' => 'O','Ὧ' => 'O','ᾨ' => 'O','ᾩ' => 'O','ᾪ' => 'O',
    'ᾫ' => 'O','ᾬ' => 'O','ᾭ' => 'O','ᾮ' => 'O','ᾯ' => 'O','Ὼ' => 'O',
    'ῼ' => 'O','α' => 'a','ά' => 'a','ἀ' => 'a','ἁ' => 'a','ἂ' => 'a',
    'ἃ' => 'a','ἄ' => 'a','ἅ' => 'a','ἆ' => 'a','ἇ' => 'a','ᾀ' => 'a',
    'ᾁ' => 'a','ᾂ' => 'a','ᾃ' => 'a','ᾄ' => 'a','ᾅ' => 'a','ᾆ' => 'a',
    'ᾇ' => 'a','ὰ' => 'a','ᾰ' => 'a','ᾱ' => 'a','ᾲ' => 'a','ᾳ' => 'a',
    'ᾴ' => 'a','ᾶ' => 'a','ᾷ' => 'a','β' => 'b','γ' => 'g','δ' => 'd',
    'ε' => 'e','έ' => 'e','ἐ' => 'e','ἑ' => 'e','ἒ' => 'e','ἓ' => 'e',
    'ἔ' => 'e','ἕ' => 'e','ὲ' => 'e','ζ' => 'z','η' => 'i','ή' => 'i',
    'ἠ' => 'i','ἡ' => 'i','ἢ' => 'i','ἣ' => 'i','ἤ' => 'i','ἥ' => 'i',
    'ἦ' => 'i','ἧ' => 'i','ᾐ' => 'i','ᾑ' => 'i','ᾒ' => 'i','ᾓ' => 'i',
    'ᾔ' => 'i','ᾕ' => 'i','ᾖ' => 'i','ᾗ' => 'i','ὴ' => 'i','ῂ' => 'i',
    'ῃ' => 'i','ῄ' => 'i','ῆ' => 'i','ῇ' => 'i','θ' => 't','ι' => 'i',
    'ί' => 'i','ϊ' => 'i','ΐ' => 'i','ἰ' => 'i','ἱ' => 'i','ἲ' => 'i',
    'ἳ' => 'i','ἴ' => 'i','ἵ' => 'i','ἶ' => 'i','ἷ' => 'i','ὶ' => 'i',
    'ῐ' => 'i','ῑ' => 'i','ῒ' => 'i','ῖ' => 'i','ῗ' => 'i','κ' => 'k',
    'λ' => 'l','μ' => 'm','ν' => 'n','ξ' => 'k','ο' => 'o','ό' => 'o',
    'ὀ' => 'o','ὁ' => 'o','ὂ' => 'o','ὃ' => 'o','ὄ' => 'o','ὅ' => 'o',
    'ὸ' => 'o','π' => 'p','ρ' => 'r','ῤ' => 'r','ῥ' => 'r','σ' => 's',
    'ς' => 's','τ' => 't','υ' => 'y','ύ' => 'y','ϋ' => 'y','ΰ' => 'y',
    'ὐ' => 'y','ὑ' => 'y','ὒ' => 'y','ὓ' => 'y','ὔ' => 'y','ὕ' => 'y',
    'ὖ' => 'y','ὗ' => 'y','ὺ' => 'y','ῠ' => 'y','ῡ' => 'y','ῢ' => 'y',
    'ῦ' => 'y','ῧ' => 'y','φ' => 'f','χ' => 'x','ψ' => 'p','ω' => 'o',
    'ώ' => 'o','ὠ' => 'o','ὡ' => 'o','ὢ' => 'o','ὣ' => 'o','ὤ' => 'o',
    'ὥ' => 'o','ὦ' => 'o','ὧ' => 'o','ᾠ' => 'o','ᾡ' => 'o','ᾢ' => 'o',
    'ᾣ' => 'o','ᾤ' => 'o','ᾥ' => 'o','ᾦ' => 'o','ᾧ' => 'o','ὼ' => 'o',
    'ῲ' => 'o','ῳ' => 'o','ῴ' => 'o','ῶ' => 'o','ῷ' => 'o','А' => 'A',
    'Б' => 'B','В' => 'V','Г' => 'G','Д' => 'D','Е' => 'E','Ё' => 'E',
    'Ж' => 'Z','З' => 'Z','И' => 'I','Й' => 'I','К' => 'K','Л' => 'L',
    'М' => 'M','Н' => 'N','О' => 'O','П' => 'P','Р' => 'R','С' => 'S',
    'Т' => 'T','У' => 'U','Ф' => 'F','Х' => 'K','Ц' => 'T','Ч' => 'C',
    'Ш' => 'S','Щ' => 'S','Ы' => 'Y','Э' => 'E','Ю' => 'Y','Я' => 'Y',
    'а' => 'A','б' => 'B','в' => 'V','г' => 'G','д' => 'D','е' => 'E',
    'ё' => 'E','ж' => 'Z','з' => 'Z','и' => 'I','й' => 'I','к' => 'K',
    'л' => 'L','м' => 'M','н' => 'N','о' => 'O','п' => 'P','р' => 'R',
    'с' => 'S','т' => 'T','у' => 'U','ф' => 'F','х' => 'K','ц' => 'T',
    'ч' => 'C','ш' => 'S','щ' => 'S','ы' => 'Y','э' => 'E','ю' => 'Y',
    'я' => 'Y','ð' => 'd','Ð' => 'D','þ' => 't','Þ' => 'T','ა' => 'a',
    'ბ' => 'b','გ' => 'g','დ' => 'd','ე' => 'e','ვ' => 'v','ზ' => 'z',
    'თ' => 't','ი' => 'i','კ' => 'k','ლ' => 'l','მ' => 'm','ნ' => 'n',
    'ო' => 'o','პ' => 'p','ჟ' => 'z','რ' => 'r','ს' => 's','ტ' => 't',
    'უ' => 'u','ფ' => 'p','ქ' => 'k','ღ' => 'g','ყ' => 'q','შ' => 's',
    'ჩ' => 'c','ც' => 't','ძ' => 'd','წ' => 't','ჭ' => 'c','ხ' => 'k',
    'ჯ' => 'j','ჰ' => 'h'
    );
    $str = str_replace( array_keys( $transliteration ),
                        array_values( $transliteration ),
                        $str);
    return $str;
}
//- remove_accents()

【讨论】：

这里还有几个要补充的：'ʼ' => "'",'̧' => '','ḩ' => 'h', 'ʼ'=>"'", '‘'=>"'", '’'=>"'", 'ừ'=>'u', 'ế'=>'e', 'ả'=>'a', 'ị'=>'i', 'ậ'=>'a', 'ệ'=>'e', 'ỉ'=>'i', 'ộ'=>'o', 'ồ'=>'o', 'ề'=>'e', 'ơ'=>'o', 'ạ'=>'a', 'ẵ'=>'a', 'ư'=>'u', 'ắ'=>'a', 'ằ'=>'a', 'ầ'=>'a', 'ḑ'=>'d', 'Ḩ'=>'H', 'Ḑ'=>'D', 'ḑ'=>'d', 'ş'=>'s', 'ā'=>'a', 'ţ'=>'t',

【解决方案4】：

短 str_replace 与自定义字符一起使用：

<?php
  $original_string    = "¿Dónde está el niño que vive aquí? En el témpano o en el iglú. ÁFRICA, MÉXICO, ÍNDICE, CANCIÓN y NÚMERO.";

  $some_special_chars = array("á", "é", "í", "ó", "ú", "Á", "É", "Í", "Ó", "Ú", "ñ", "Ñ");
  $replacement_chars  = array("a", "e", "i", "o", "u", "A", "E", "I", "O", "U", "n", "N");

  $replaced_string    = str_replace($some_special_chars, $replacement_chars, $original_string);

  echo $replaced_string; // outputs '¿Donde esta el nino que vive aqui? En el tempano o en el iglu. AFRICA, MEXICO, INDICE, CANCION y NUMERO.'
?>

【讨论】：

【解决方案5】：

尤其是在将文本相互匹配或与关键字匹配时，对之前的文本进行规范化很有帮助。以下函数从给定的 UTF8 编码文本中删除所有变音符号（如重音符号）并返回 ASCii 文本。

确保安装了 PHP-Normalizer-extension（intl 和 icu）。

提示：您可能还希望在执行匹配过程之前将文本映射为小写 ...

<?php

function normalizeUtf8String( $s)
{
    // Normalizer-class missing!
    if (! class_exists("Normalizer", $autoload = false))
        return $original_string;


    // maps German (umlauts) and other European characters onto two characters before just removing diacritics
    $s    = preg_replace( '@\x{00c4}@u'    , "AE",    $s );    // umlaut Ä => AE
    $s    = preg_replace( '@\x{00d6}@u'    , "OE",    $s );    // umlaut Ö => OE
    $s    = preg_replace( '@\x{00dc}@u'    , "UE",    $s );    // umlaut Ü => UE
    $s    = preg_replace( '@\x{00e4}@u'    , "ae",    $s );    // umlaut ä => ae
    $s    = preg_replace( '@\x{00f6}@u'    , "oe",    $s );    // umlaut ö => oe
    $s    = preg_replace( '@\x{00fc}@u'    , "ue",    $s );    // umlaut ü => ue
    $s    = preg_replace( '@\x{00f1}@u'    , "ny",    $s );    // ñ => ny
    $s    = preg_replace( '@\x{00ff}@u'    , "yu",    $s );    // ÿ => yu


    // maps special characters (characters with diacritics) on their base-character followed by the diacritical mark
        // exmaple:  Ú => U´,  á => a`
    $s    = Normalizer::normalize( $s, Normalizer::FORM_D );


    $s    = preg_replace( '@\pM@u'        , "",    $s );    // removes diacritics


    $s    = preg_replace( '@\x{00df}@u'    , "ss",    $s );    // maps German ß onto ss
    $s    = preg_replace( '@\x{00c6}@u'    , "AE",    $s );    // Æ => AE
    $s    = preg_replace( '@\x{00e6}@u'    , "ae",    $s );    // æ => ae
    $s    = preg_replace( '@\x{0132}@u'    , "IJ",    $s );    // ? => IJ
    $s    = preg_replace( '@\x{0133}@u'    , "ij",    $s );    // ? => ij
    $s    = preg_replace( '@\x{0152}@u'    , "OE",    $s );    // Œ => OE
    $s    = preg_replace( '@\x{0153}@u'    , "oe",    $s );    // œ => oe

    $s    = preg_replace( '@\x{00d0}@u'    , "D",    $s );    // Ð => D
    $s    = preg_replace( '@\x{0110}@u'    , "D",    $s );    // Ð => D
    $s    = preg_replace( '@\x{00f0}@u'    , "d",    $s );    // ð => d
    $s    = preg_replace( '@\x{0111}@u'    , "d",    $s );    // d => d
    $s    = preg_replace( '@\x{0126}@u'    , "H",    $s );    // H => H
    $s    = preg_replace( '@\x{0127}@u'    , "h",    $s );    // h => h
    $s    = preg_replace( '@\x{0131}@u'    , "i",    $s );    // i => i
    $s    = preg_replace( '@\x{0138}@u'    , "k",    $s );    // ? => k
    $s    = preg_replace( '@\x{013f}@u'    , "L",    $s );    // ? => L
    $s    = preg_replace( '@\x{0141}@u'    , "L",    $s );    // L => L
    $s    = preg_replace( '@\x{0140}@u'    , "l",    $s );    // ? => l
    $s    = preg_replace( '@\x{0142}@u'    , "l",    $s );    // l => l
    $s    = preg_replace( '@\x{014a}@u'    , "N",    $s );    // ? => N
    $s    = preg_replace( '@\x{0149}@u'    , "n",    $s );    // ? => n
    $s    = preg_replace( '@\x{014b}@u'    , "n",    $s );    // ? => n
    $s    = preg_replace( '@\x{00d8}@u'    , "O",    $s );    // Ø => O
    $s    = preg_replace( '@\x{00f8}@u'    , "o",    $s );    // ø => o
    $s    = preg_replace( '@\x{017f}@u'    , "s",    $s );    // ? => s
    $s    = preg_replace( '@\x{00de}@u'    , "T",    $s );    // Þ => T
    $s    = preg_replace( '@\x{0166}@u'    , "T",    $s );    // T => T
    $s    = preg_replace( '@\x{00fe}@u'    , "t",    $s );    // þ => t
    $s    = preg_replace( '@\x{0167}@u'    , "t",    $s );    // t => t

    // remove all non-ASCii characters
    $s    = preg_replace( '@[^\0-\x80]@u'    , "",    $s );


    // possible errors in UTF8-regular-expressions
    if (empty($s))
        return $original_string;
    else
        return $s;
}
?>

以上功能主要基于以下文章： http://ahinea.com/en/tech/accented-translate.html

【讨论】：

当我用这个生成 xml 时，会为我生成一个空的 xml 文件。如何正确使用这个东西

【解决方案6】：

使用 PEAR I18N_UnicodeNormalizer-1.0.0

include('…');

echo preg_replace(
 '/(\P{L})/ui', // replace all except members of Unicode class "letters", case insensitive
 '', // with nothing
 I18N_UnicodeNormalizer::toNFKD('ÅÉÏÔÙåéïôù') // ù → u + `
);

→ AEIOUaeiou

【讨论】：

【解决方案7】：

如果其他解决方案都不适合您，以下是适合我的解决方案：

<?php

$string = "áéíóúÁ—whatever";

// create an array of the hex codes of the characters you want to replace (formatted as shown) and whatever you want to replace them with.
$characters = array(
  "[\xF3]" => "&ocacute;", //ó
  "[\xFC]" => "&uuml;", //ü
  "[\xF1]" => "&ntilde;", //ñ
  "[\xEB]" => "&euml;", //ë
  "[\xE9]" => "&eacute;", //é
  "[\xBD]" => "&frac12;", //½
);
// note that you must use a two-digit hex code for whatever reason.
// So, for example, although the hex code for an em dash is 2014, you have to use 97 instead. ("[\x97]" => "&mdash;")

// separate the key->value array into two separate arrays. Or just make two arrays from the beginning, but it's easier to read this way.
foreach ($characters as $hex => $html) {
  $replaceThis[] = $hex;
  $replaceWith[] = $html;
}

$string = preg_replace($replaceThis, $replaceWith, $string);

?>

它可能不是最优雅的解决方案，但它可以工作并且不需要正则表达式知识。

【讨论】：

【解决方案8】：

人们经常使用str_replace 或strtr 和一大串字符来转换“from”和“to”——即使这看起来不太漂亮......

我想，另一种解决方案可能是使用 iconv 之类的选项和 //TRANSLIT 选项——但据我记得，这并不总是有效...

另外，如果您使用的是 PHP 5.3，新的 Normalizer 类可能会很有趣；-)

【讨论】：

帕斯卡，请查看我对 WaffleMatt 答案的评论。