如何从 PHP 字符串中删除重音符号?

我试图删除 PHP 字符串中的重音符号,作为使该字符串在 URL 中可用的第一步。

我使用以下代码:

$input = "Fóø Bår";


setlocale(LC_ALL, "en_US.utf8");
$output = iconv("utf-8", "ascii//TRANSLIT", $input);


print($output);

我期望的输出是这样的:

F'oo Bar

但是,这些重音字符没有被音译,而是用问号代替:

F?? B?r

我在网上找到的一切都表明,设置区域设置将解决这个问题,但我已经在这样做了。我已经查过以下细节了:

  1. 服务器支持我正在设置的语言环境(包括在 locale -a生成的列表中)
  2. 服务器版本的 iconv (包含在 iconv -l生成的列表中)支持源和目标编码(UTF-8和 ASCII)
  3. 输入字符串是 UTF-8编码的(按照 墨卡托的回答中的建议,使用 PHP 的 mb_check_encoding函数进行验证)
  4. setlocale的调用成功(它返回 'en_US.utf8'而不是 FALSE)

问题的原因:

服务器使用了错误的 iconv 实现。它有 Glibc版本,而不是所需的 Libiconv版本。

注意,某些系统上的 iconv 函数可能不会像您期望的那样工作。在这种情况下,最好安装 GNU libiconv 库。最终很可能会得到更加一致的结果。
PHP 手册对 iconv 的介绍

有关 PHP 使用的 iconv 实现的详细信息包含在 phpinfo函数的输出中。

(我无法在我正在为这个项目工作的服务器上使用正确的 iconv 库重新编译 PHP,所以我接受的答案是下面这个在没有 iconv 支持的情况下对删除重音最有用的答案。)

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I think the problem here is that your encodings consider ä and å different symbols to 'a'. In fact, the PHP documentation for strtr offers a sample for removing accents the ugly way :(

http://ie2.php.net/strtr

You could use urlencode. Does not quite do what you want (remove accents), but will give you a url usable string

$output = urlencode ($input);

In Perl I could use a translate regex, but I cannot think of the PHP equivalent

$input =~ tr/áâàå/aaaa/;

etc...

you could do this using preg_replace

$patterns[0] = '/[á|â|à|å|ä]/';
$patterns[1] = '/[ð|é|ê|è|ë]/';
$patterns[2] = '/[í|î|ì|ï]/';
$patterns[3] = '/[ó|ô|ò|ø|õ|ö]/';
$patterns[4] = '/[ú|û|ù|ü]/';
$patterns[5] = '/æ/';
$patterns[6] = '/ç/';
$patterns[7] = '/ß/';
$replacements[0] = 'a';
$replacements[1] = 'e';
$replacements[2] = 'i';
$replacements[3] = 'o';
$replacements[4] = 'u';
$replacements[5] = 'ae';
$replacements[6] = 'c';
$replacements[7] = 'ss';


$output = preg_replace($patterns, $replacements, $input);

(Please note this was typed from a foggy beer ridden Friday after noon memory, so may not be 100% correct)

or you could make a hash table and do a replacement based off of that.

I agree with georgebrock's comment.

If you find a way to get //TRANSLIT to work, you can build friendly URLs:

  1. use iconv with //TRANSLIT ñ => n~
    • remove non-alphanumeric non-whitespace chars inside words: $url = preg_replace( '/(\w)[^\w\s](\w)/', '$1$2', $url );
    • replace remaining separations: $url = preg_replace( '/[^a-z0-9]+/', '-', $url );
    • remove double/leading/traling: $url = preg_replace( '-', e.g. '/(?:(^|\-)\-+|\-$)/', '', $url );

If you can't get it to work, replace setp 1 with strtr/character-based replacement, like Xetius' solution.

I can't reproduce your problem. I get the expected result.

How exactly are you using mb_detect_encoding() to verify your string is in fact UTF-8?

If I simply call mb_detect_encoding($input) on both a UTF-8 and ISO-8859-1 encoded version of your string, both of them return "UTF-8", so that function isn't particularly reliable.

iconv() gives me a PHP "notice" when it gets the wrongly encoded string and only echoes "F", but that might just be because of different PHP/iconv settings/versions (?).

I suggest to you try calling mb_check_encoding($input, "utf-8") first to verify that your string really is UTF-8. I think it probably isn't.

One of the tricks I stumbled upon on the web was using htmlentities then stripping the encoded character :

$stripped = preg_replace('`&[^;]+;`','',htmlentities($string));

Not perfect but it does work well in some case.

But, you're writing about creating an URL string, so urlencode and its counterpart urldecode may be better. Or, if you are creating a query string, use this last function : http_build_query.

When using iconv, the parameter locale must be set:

function test_enc($text = 'ěščřžýáíé ĚŠČŘŽÝÁÍÉ fóø bår FÓØ BÅR æ')
{
echo '<tt>';
echo iconv('utf8', 'ascii//TRANSLIT', $text);
echo '</tt><br/>';
}


test_enc();
setlocale(LC_ALL, 'cs_CZ.utf8');
test_enc();
setlocale(LC_ALL, 'en_US.utf8');
test_enc();

Yields into:

????????? ????????? f?? b?r F?? B?R ae
escrzyaie ESCRZYAIE fo? bar FO? BAR ae
escrzyaie ESCRZYAIE fo? bar FO? BAR ae

Another locales then cs_CZ and en_US I haven't installed and I can't test it.

In C# I see solution using translation to unicode normalized form - accents are splitted out and then filtered via nonspacing unicode category.

This is a piece of code I found and use often:

function stripAccents($stripAccents){
return strtr($stripAccents,'àáâãäçèéêëìíîïñòóôõöùúûüýÿÀÁÂÃÄÇÈÉÊËÌÍÎÏÑÒÓÔÕÖÙÚÛÜÝ','aaaaaceeeeiiiinooooouuuuyyAAAAACEEEEIIIINOOOOOUUUUY');
}

What about the WordPress implementation?

function remove_accents($string) {
if ( !preg_match('/[\x80-\xff]/', $string) )
return $string;


$chars = array(
// Decompositions for Latin-1 Supplement
chr(195).chr(128) => 'A', chr(195).chr(129) => 'A',
chr(195).chr(130) => 'A', chr(195).chr(131) => 'A',
chr(195).chr(132) => 'A', chr(195).chr(133) => 'A',
chr(195).chr(135) => 'C', chr(195).chr(136) => 'E',
chr(195).chr(137) => 'E', chr(195).chr(138) => 'E',
chr(195).chr(139) => 'E', chr(195).chr(140) => 'I',
chr(195).chr(141) => 'I', chr(195).chr(142) => 'I',
chr(195).chr(143) => 'I', chr(195).chr(145) => 'N',
chr(195).chr(146) => 'O', chr(195).chr(147) => 'O',
chr(195).chr(148) => 'O', chr(195).chr(149) => 'O',
chr(195).chr(150) => 'O', chr(195).chr(153) => 'U',
chr(195).chr(154) => 'U', chr(195).chr(155) => 'U',
chr(195).chr(156) => 'U', chr(195).chr(157) => 'Y',
chr(195).chr(159) => 's', chr(195).chr(160) => 'a',
chr(195).chr(161) => 'a', chr(195).chr(162) => 'a',
chr(195).chr(163) => 'a', chr(195).chr(164) => 'a',
chr(195).chr(165) => 'a', chr(195).chr(167) => 'c',
chr(195).chr(168) => 'e', chr(195).chr(169) => 'e',
chr(195).chr(170) => 'e', chr(195).chr(171) => 'e',
chr(195).chr(172) => 'i', chr(195).chr(173) => 'i',
chr(195).chr(174) => 'i', chr(195).chr(175) => 'i',
chr(195).chr(177) => 'n', chr(195).chr(178) => 'o',
chr(195).chr(179) => 'o', chr(195).chr(180) => 'o',
chr(195).chr(181) => 'o', chr(195).chr(182) => 'o',
chr(195).chr(182) => 'o', chr(195).chr(185) => 'u',
chr(195).chr(186) => 'u', chr(195).chr(187) => 'u',
chr(195).chr(188) => 'u', chr(195).chr(189) => 'y',
chr(195).chr(191) => 'y',
// Decompositions for Latin Extended-A
chr(196).chr(128) => 'A', chr(196).chr(129) => 'a',
chr(196).chr(130) => 'A', chr(196).chr(131) => 'a',
chr(196).chr(132) => 'A', chr(196).chr(133) => 'a',
chr(196).chr(134) => 'C', chr(196).chr(135) => 'c',
chr(196).chr(136) => 'C', chr(196).chr(137) => 'c',
chr(196).chr(138) => 'C', chr(196).chr(139) => 'c',
chr(196).chr(140) => 'C', chr(196).chr(141) => 'c',
chr(196).chr(142) => 'D', chr(196).chr(143) => 'd',
chr(196).chr(144) => 'D', chr(196).chr(145) => 'd',
chr(196).chr(146) => 'E', chr(196).chr(147) => 'e',
chr(196).chr(148) => 'E', chr(196).chr(149) => 'e',
chr(196).chr(150) => 'E', chr(196).chr(151) => 'e',
chr(196).chr(152) => 'E', chr(196).chr(153) => 'e',
chr(196).chr(154) => 'E', chr(196).chr(155) => 'e',
chr(196).chr(156) => 'G', chr(196).chr(157) => 'g',
chr(196).chr(158) => 'G', chr(196).chr(159) => 'g',
chr(196).chr(160) => 'G', chr(196).chr(161) => 'g',
chr(196).chr(162) => 'G', chr(196).chr(163) => 'g',
chr(196).chr(164) => 'H', chr(196).chr(165) => 'h',
chr(196).chr(166) => 'H', chr(196).chr(167) => 'h',
chr(196).chr(168) => 'I', chr(196).chr(169) => 'i',
chr(196).chr(170) => 'I', chr(196).chr(171) => 'i',
chr(196).chr(172) => 'I', chr(196).chr(173) => 'i',
chr(196).chr(174) => 'I', chr(196).chr(175) => 'i',
chr(196).chr(176) => 'I', chr(196).chr(177) => 'i',
chr(196).chr(178) => 'IJ',chr(196).chr(179) => 'ij',
chr(196).chr(180) => 'J', chr(196).chr(181) => 'j',
chr(196).chr(182) => 'K', chr(196).chr(183) => 'k',
chr(196).chr(184) => 'k', chr(196).chr(185) => 'L',
chr(196).chr(186) => 'l', chr(196).chr(187) => 'L',
chr(196).chr(188) => 'l', chr(196).chr(189) => 'L',
chr(196).chr(190) => 'l', chr(196).chr(191) => 'L',
chr(197).chr(128) => 'l', chr(197).chr(129) => 'L',
chr(197).chr(130) => 'l', chr(197).chr(131) => 'N',
chr(197).chr(132) => 'n', chr(197).chr(133) => 'N',
chr(197).chr(134) => 'n', chr(197).chr(135) => 'N',
chr(197).chr(136) => 'n', chr(197).chr(137) => 'N',
chr(197).chr(138) => 'n', chr(197).chr(139) => 'N',
chr(197).chr(140) => 'O', chr(197).chr(141) => 'o',
chr(197).chr(142) => 'O', chr(197).chr(143) => 'o',
chr(197).chr(144) => 'O', chr(197).chr(145) => 'o',
chr(197).chr(146) => 'OE',chr(197).chr(147) => 'oe',
chr(197).chr(148) => 'R',chr(197).chr(149) => 'r',
chr(197).chr(150) => 'R',chr(197).chr(151) => 'r',
chr(197).chr(152) => 'R',chr(197).chr(153) => 'r',
chr(197).chr(154) => 'S',chr(197).chr(155) => 's',
chr(197).chr(156) => 'S',chr(197).chr(157) => 's',
chr(197).chr(158) => 'S',chr(197).chr(159) => 's',
chr(197).chr(160) => 'S', chr(197).chr(161) => 's',
chr(197).chr(162) => 'T', chr(197).chr(163) => 't',
chr(197).chr(164) => 'T', chr(197).chr(165) => 't',
chr(197).chr(166) => 'T', chr(197).chr(167) => 't',
chr(197).chr(168) => 'U', chr(197).chr(169) => 'u',
chr(197).chr(170) => 'U', chr(197).chr(171) => 'u',
chr(197).chr(172) => 'U', chr(197).chr(173) => 'u',
chr(197).chr(174) => 'U', chr(197).chr(175) => 'u',
chr(197).chr(176) => 'U', chr(197).chr(177) => 'u',
chr(197).chr(178) => 'U', chr(197).chr(179) => 'u',
chr(197).chr(180) => 'W', chr(197).chr(181) => 'w',
chr(197).chr(182) => 'Y', chr(197).chr(183) => 'y',
chr(197).chr(184) => 'Y', chr(197).chr(185) => 'Z',
chr(197).chr(186) => 'z', chr(197).chr(187) => 'Z',
chr(197).chr(188) => 'z', chr(197).chr(189) => 'Z',
chr(197).chr(190) => 'z', chr(197).chr(191) => 's'
);


$string = strtr($string, $chars);


return $string;
}

To understand what this function does, check the conversion table:

À => A
Á => A
 => A
à => A
Ä => A
Å => A
Ç => C
È => E
É => E
Ê => E
Ë => E
Ì => I
Í => I
Î => I
Ï => I
Ñ => N
Ò => O
Ó => O
Ô => O
Õ => O
Ö => O
Ù => U
Ú => U
Û => U
Ü => U
Ý => Y
ß => s
à => a
á => a
â => a
ã => a
ä => a
å => a
ç => c
è => e
é => e
ê => e
ë => e
ì => i
í => i
î => i
ï => i
ñ => n
ò => o
ó => o
ô => o
õ => o
ö => o
ù => u
ú => u
û => u
ü => u
ý => y
ÿ => y
Ā => A
ā => a
Ă => A
ă => a
Ą => A
ą => a
Ć => C
ć => c
Ĉ => C
ĉ => c
Ċ => C
ċ => c
Č => C
č => c
Ď => D
ď => d
Đ => D
đ => d
Ē => E
ē => e
Ĕ => E
ĕ => e
Ė => E
ė => e
Ę => E
ę => e
Ě => E
ě => e
Ĝ => G
ĝ => g
Ğ => G
ğ => g
Ġ => G
ġ => g
Ģ => G
ģ => g
Ĥ => H
ĥ => h
Ħ => H
ħ => h
Ĩ => I
ĩ => i
Ī => I
ī => i
Ĭ => I
ĭ => i
Į => I
į => i
İ => I
ı => i
IJ => IJ
ij => ij
Ĵ => J
ĵ => j
Ķ => K
ķ => k
ĸ => k
Ĺ => L
ĺ => l
Ļ => L
ļ => l
Ľ => L
ľ => l
Ŀ => L
ŀ => l
Ł => L
ł => l
Ń => N
ń => n
Ņ => N
ņ => n
Ň => N
ň => n
ʼn => N
Ŋ => n
ŋ => N
Ō => O
ō => o
Ŏ => O
ŏ => o
Ő => O
ő => o
Œ => OE
œ => oe
Ŕ => R
ŕ => r
Ŗ => R
ŗ => r
Ř => R
ř => r
Ś => S
ś => s
Ŝ => S
ŝ => s
Ş => S
ş => s
Š => S
š => s
Ţ => T
ţ => t
Ť => T
ť => t
Ŧ => T
ŧ => t
Ũ => U
ũ => u
Ū => U
ū => u
Ŭ => U
ŭ => u
Ů => U
ů => u
Ű => U
ű => u
Ų => U
ų => u
Ŵ => W
ŵ => w
Ŷ => Y
ŷ => y
Ÿ => Y
Ź => Z
ź => z
Ż => Z
ż => z
Ž => Z
ž => z
ſ => s

You can generate the conversion table yourself by simply iterating over the $chars array of the function:

foreach($chars as $k=>$v) {
printf("%s -> %s", $k, $v);
}

UTF-8 friendly version of the simple function posted above by Gino:

function stripAccents($str) {
return strtr(utf8_decode($str), utf8_decode('àáâãäçèéêëìíîïñòóôõöùúûüýÿÀÁÂÃÄÇÈÉÊËÌÍÎÏÑÒÓÔÕÖÙÚÛÜÝ'), 'aaaaaceeeeiiiinooooouuuuyyAAAAACEEEEIIIINOOOOOUUUUY');
}

Had to come to this because my php document was UTF-8 encoded.

Hope it helps.

Indeed is a matter of taste. There are many flavors for converting such letters.

function replaceAccents($str)
{
$a = array('À', 'Á', 'Â', 'Ã', 'Ä', 'Å', 'Æ', 'Ç', 'È', 'É', 'Ê', 'Ë', 'Ì', 'Í', 'Î', 'Ï', 'Ð', 'Ñ', 'Ò', 'Ó', 'Ô', 'Õ', 'Ö', 'Ø', 'Ù', 'Ú', 'Û', 'Ü', 'Ý', 'ß', 'à', 'á', 'â', 'ã', 'ä', 'å', 'æ', 'ç', 'è', 'é', 'ê', 'ë', 'ì', 'í', 'î', 'ï', 'ñ', 'ò', 'ó', 'ô', 'õ', 'ö', 'ø', 'ù', 'ú', 'û', 'ü', 'ý', 'ÿ', 'Ā', 'ā', 'Ă', 'ă', 'Ą', 'ą', 'Ć', 'ć', 'Ĉ', 'ĉ', 'Ċ', 'ċ', 'Č', 'č', 'Ď', 'ď', 'Đ', 'đ', 'Ē', 'ē', 'Ĕ', 'ĕ', 'Ė', 'ė', 'Ę', 'ę', 'Ě', 'ě', 'Ĝ', 'ĝ', 'Ğ', 'ğ', 'Ġ', 'ġ', 'Ģ', 'ģ', 'Ĥ', 'ĥ', 'Ħ', 'ħ', 'Ĩ', 'ĩ', 'Ī', 'ī', 'Ĭ', 'ĭ', 'Į', 'į', 'İ', 'ı', 'IJ', 'ij', 'Ĵ', 'ĵ', 'Ķ', 'ķ', 'Ĺ', 'ĺ', 'Ļ', 'ļ', 'Ľ', 'ľ', 'Ŀ', 'ŀ', 'Ł', 'ł', 'Ń', 'ń', 'Ņ', 'ņ', 'Ň', 'ň', 'ʼn', 'Ō', 'ō', 'Ŏ', 'ŏ', 'Ő', 'ő', 'Œ', 'œ', 'Ŕ', 'ŕ', 'Ŗ', 'ŗ', 'Ř', 'ř', 'Ś', 'ś', 'Ŝ', 'ŝ', 'Ş', 'ş', 'Š', 'š', 'Ţ', 'ţ', 'Ť', 'ť', 'Ŧ', 'ŧ', 'Ũ', 'ũ', 'Ū', 'ū', 'Ŭ', 'ŭ', 'Ů', 'ů', 'Ű', 'ű', 'Ų', 'ų', 'Ŵ', 'ŵ', 'Ŷ', 'ŷ', 'Ÿ', 'Ź', 'ź', 'Ż', 'ż', 'Ž', 'ž', 'ſ', 'ƒ', 'Ơ', 'ơ', 'Ư', 'ư', 'Ǎ', 'ǎ', 'Ǐ', 'ǐ', 'Ǒ', 'ǒ', 'Ǔ', 'ǔ', 'Ǖ', 'ǖ', 'Ǘ', 'ǘ', 'Ǚ', 'ǚ', 'Ǜ', 'ǜ', 'Ǻ', 'ǻ', 'Ǽ', 'ǽ', 'Ǿ', 'ǿ');
$b = array('A', 'A', 'A', 'A', 'A', 'A', 'AE', 'C', 'E', 'E', 'E', 'E', 'I', 'I', 'I', 'I', 'D', 'N', 'O', 'O', 'O', 'O', 'O', 'O', 'U', 'U', 'U', 'U', 'Y', 's', 'a', 'a', 'a', 'a', 'a', 'a', 'ae', 'c', 'e', 'e', 'e', 'e', 'i', 'i', 'i', 'i', 'n', 'o', 'o', 'o', 'o', 'o', 'o', 'u', 'u', 'u', 'u', 'y', 'y', 'A', 'a', 'A', 'a', 'A', 'a', 'C', 'c', 'C', 'c', 'C', 'c', 'C', 'c', 'D', 'd', 'D', 'd', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'E', 'e', 'G', 'g', 'G', 'g', 'G', 'g', 'G', 'g', 'H', 'h', 'H', 'h', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'I', 'i', 'IJ', 'ij', 'J', 'j', 'K', 'k', 'L', 'l', 'L', 'l', 'L', 'l', 'L', 'l', 'l', 'l', 'N', 'n', 'N', 'n', 'N', 'n', 'n', 'O', 'o', 'O', 'o', 'O', 'o', 'OE', 'oe', 'R', 'r', 'R', 'r', 'R', 'r', 'S', 's', 'S', 's', 'S', 's', 'S', 's', 'T', 't', 'T', 't', 'T', 't', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'W', 'w', 'Y', 'y', 'Y', 'Z', 'z', 'Z', 'z', 'Z', 'z', 's', 'f', 'O', 'o', 'U', 'u', 'A', 'a', 'I', 'i', 'O', 'o', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'U', 'u', 'A', 'a', 'AE', 'ae', 'O', 'o');
return str_replace($a, $b, $str);
}

WordPress' implementation is definitly the safest for UTF8 strings. For Latin1 strings, a simple strtr does the job, but ensure you're saving your script in LATIN1 format, not UTF-8.

Merged Cazuma Nii Cavalcanti's implementation with Junior Mayhé's char list, hoping to save some time for some of you.

function stripAccents($str) {
return strtr(utf8_decode($str), utf8_decode('ÀÁÂÃÄÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝßàáâãäåæçèéêëìíîïñòóôõöøùúûüýÿĀāĂ㥹ĆćĈĉĊċČčĎďĐđĒēĔĕĖėĘęĚěĜĝĞğĠġĢģĤĥĦħĨĩĪīĬĭĮįİıIJijĴĵĶķĹĺĻļĽľĿŀŁłŃńŅņŇňʼnŌōŎŏŐőŒœŔŕŖŗŘřŚśŜŝŞşŠšŢţŤťŦŧŨũŪūŬŭŮůŰűŲųŴŵŶŷŸŹźŻżŽžſƒƠơƯưǍǎǏǐǑǒǓǔǕǖǗǘǙǚǛǜǺǻǼǽǾǿ'), 'AAAAAAAECEEEEIIIIDNOOOOOOUUUUYsaaaaaaaeceeeeiiiinoooooouuuuyyAaAaAaCcCcCcCcDdDdEeEeEeEeEeGgGgGgGgHhHhIiIiIiIiIiIJijJjKkLlLlLlLlllNnNnNnnOoOoOoOEoeRrRrRrSsSsSsSsTtTtTtUuUuUuUuUuUuWwYyYZzZzZzsfOoUuAaIiOoUuUuUuUuUuAaAEaeOo');
}

The easiest way is to use iconv() PHP native function.

 echo iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE', "Thîs îs à vêry wrong séntènce!");


// output: This is a very wrong sentence!

You can use an array key => value style to use with strtr() safely for UTF-8 characters even if they are multi-bytes.

function no_accent($str){
$accents = array('À' => 'A', 'Á' => 'A', 'Â' => 'A', 'Ã' => 'A', 'Ä' => 'A', 'Å' => 'A', 'à' => 'a', 'á' => 'a', 'â' => 'a', 'ã' => 'a', 'ä' => 'a', 'å' => 'a', 'Ā' => 'A', 'ā' => 'a', 'Ă' => 'A', 'ă' => 'a', 'Ą' => 'A', 'ą' => 'a', 'Ç' => 'C', 'ç' => 'c', 'Ć' => 'C', 'ć' => 'c', 'Ĉ' => 'C', 'ĉ' => 'c', 'Ċ' => 'C', 'ċ' => 'c', 'Č' => 'C', 'č' => 'c', 'Ð' => 'D', 'ð' => 'd', 'Ď' => 'D', 'ď' => 'd', 'Đ' => 'D', 'đ' => 'd', 'È' => 'E', 'É' => 'E', 'Ê' => 'E', 'Ë' => 'E', 'è' => 'e', 'é' => 'e', 'ê' => 'e', 'ë' => 'e', 'Ē' => 'E', 'ē' => 'e', 'Ĕ' => 'E', 'ĕ' => 'e', 'Ė' => 'E', 'ė' => 'e', 'Ę' => 'E', 'ę' => 'e', 'Ě' => 'E', 'ě' => 'e', 'Ĝ' => 'G', 'ĝ' => 'g', 'Ğ' => 'G', 'ğ' => 'g', 'Ġ' => 'G', 'ġ' => 'g', 'Ģ' => 'G', 'ģ' => 'g', 'Ĥ' => 'H', 'ĥ' => 'h', 'Ħ' => 'H', 'ħ' => 'h', 'Ì' => 'I', 'Í' => 'I', 'Î' => 'I', 'Ï' => 'I', 'ì' => 'i', 'í' => 'i', 'î' => 'i', 'ï' => 'i', 'Ĩ' => 'I', 'ĩ' => 'i', 'Ī' => 'I', 'ī' => 'i', 'Ĭ' => 'I', 'ĭ' => 'i', 'Į' => 'I', 'į' => 'i', 'İ' => 'I', 'ı' => 'i', 'Ĵ' => 'J', 'ĵ' => 'j', 'Ķ' => 'K', 'ķ' => 'k', 'ĸ' => 'k', 'Ĺ' => 'L', 'ĺ' => 'l', 'Ļ' => 'L', 'ļ' => 'l', 'Ľ' => 'L', 'ľ' => 'l', 'Ŀ' => 'L', 'ŀ' => 'l', 'Ł' => 'L', 'ł' => 'l', 'Ñ' => 'N', 'ñ' => 'n', 'Ń' => 'N', 'ń' => 'n', 'Ņ' => 'N', 'ņ' => 'n', 'Ň' => 'N', 'ň' => 'n', 'ʼn' => 'n', 'Ŋ' => 'N', 'ŋ' => 'n', 'Ò' => 'O', 'Ó' => 'O', 'Ô' => 'O', 'Õ' => 'O', 'Ö' => 'O', 'Ø' => 'O', 'ò' => 'o', 'ó' => 'o', 'ô' => 'o', 'õ' => 'o', 'ö' => 'o', 'ø' => 'o', 'Ō' => 'O', 'ō' => 'o', 'Ŏ' => 'O', 'ŏ' => 'o', 'Ő' => 'O', 'ő' => 'o', 'Ŕ' => 'R', 'ŕ' => 'r', 'Ŗ' => 'R', 'ŗ' => 'r', 'Ř' => 'R', 'ř' => 'r', 'Ś' => 'S', 'ś' => 's', 'Ŝ' => 'S', 'ŝ' => 's', 'Ş' => 'S', 'ş' => 's', 'Š' => 'S', 'š' => 's', 'ſ' => 's', 'Ţ' => 'T', 'ţ' => 't', 'Ť' => 'T', 'ť' => 't', 'Ŧ' => 'T', 'ŧ' => 't', 'Ù' => 'U', 'Ú' => 'U', 'Û' => 'U', 'Ü' => 'U', 'ù' => 'u', 'ú' => 'u', 'û' => 'u', 'ü' => 'u', 'Ũ' => 'U', 'ũ' => 'u', 'Ū' => 'U', 'ū' => 'u', 'Ŭ' => 'U', 'ŭ' => 'u', 'Ů' => 'U', 'ů' => 'u', 'Ű' => 'U', 'ű' => 'u', 'Ų' => 'U', 'ų' => 'u', 'Ŵ' => 'W', 'ŵ' => 'w', 'Ý' => 'Y', 'ý' => 'y', 'ÿ' => 'y', 'Ŷ' => 'Y', 'ŷ' => 'y', 'Ÿ' => 'Y', 'Ź' => 'Z', 'ź' => 'z', 'Ż' => 'Z', 'ż' => 'z', 'Ž' => 'Z', 'ž' => 'z');
return strtr($str, $accents);
}

Plus, you save decode/encode in UTF-8 part.

$unwanted_array = array(    '&amp;' => 'and', '&' => 'and', '@' => 'at', '©' => 'c', '®' => 'r',
'̊'=>'','̧'=>'','̨'=>'','̄'=>'','̱'=>'',
'Á'=>'a','á'=>'a','À'=>'a','à'=>'a','Ă'=>'a','ă'=>'a','ắ'=>'a','Ắ'=>'A','Ằ'=>'A',
'ằ'=>'a','ẵ'=>'a','Ẵ'=>'A','ẳ'=>'a','Ẳ'=>'A','Â'=>'a','â'=>'a','ấ'=>'a','Ấ'=>'A',
'ầ'=>'a','Ầ'=>'a','ẩ'=>'a','Ẩ'=>'A','Ǎ'=>'a','ǎ'=>'a','Å'=>'a','å'=>'a','Ǻ'=>'a',
'ǻ'=>'a','Ä'=>'a','ä'=>'a','ã'=>'a','Ã'=>'A','Ą'=>'a','ą'=>'a','Ā'=>'a','ā'=>'a',
'ả'=>'a','Ả'=>'a','Ạ'=>'A','ạ'=>'a','ặ'=>'a','Ặ'=>'A','ậ'=>'a','Ậ'=>'A','Æ'=>'ae',
'æ'=>'ae','Ǽ'=>'ae','ǽ'=>'ae','ẫ'=>'a','Ẫ'=>'A',
'Ć'=>'c','ć'=>'c','Ĉ'=>'c','ĉ'=>'c','Č'=>'c','č'=>'c','Ċ'=>'c','ċ'=>'c','Ç'=>'c','ç'=>'c',
'Ď'=>'d','ď'=>'d','Ḑ'=>'D','ḑ'=>'d','Đ'=>'d','đ'=>'d','Ḍ'=>'D','ḍ'=>'d','Ḏ'=>'D','ḏ'=>'d','ð'=>'d','Ð'=>'D',
'É'=>'e','é'=>'e','È'=>'e','è'=>'e','Ĕ'=>'e','ĕ'=>'e','ê'=>'e','ế'=>'e','Ế'=>'E','ề'=>'e',
'Ề'=>'E','Ě'=>'e','ě'=>'e','Ë'=>'e','ë'=>'e','Ė'=>'e','ė'=>'e','Ę'=>'e','ę'=>'e','Ē'=>'e',
'ē'=>'e','ệ'=>'e','Ệ'=>'E','Ə'=>'e','ə'=>'e','ẽ'=>'e','Ẽ'=>'E','ễ'=>'e',
'Ễ'=>'E','ể'=>'e','Ể'=>'E','ẻ'=>'e','Ẻ'=>'E','ẹ'=>'e','Ẹ'=>'E',
'ƒ'=>'f',
'Ğ'=>'g','ğ'=>'g','Ĝ'=>'g','ĝ'=>'g','Ǧ'=>'G','ǧ'=>'g','Ġ'=>'g','ġ'=>'g','Ģ'=>'g','ģ'=>'g',
'H̲'=>'H','h̲'=>'h','Ĥ'=>'h','ĥ'=>'h','Ȟ'=>'H','ȟ'=>'h','Ḩ'=>'H','ḩ'=>'h','Ħ'=>'h','ħ'=>'h','Ḥ'=>'H','ḥ'=>'h',
'Ỉ'=>'I','Í'=>'i','í'=>'i','Ì'=>'i','ì'=>'i','Ĭ'=>'i','ĭ'=>'i','Î'=>'i','î'=>'i','Ǐ'=>'i','ǐ'=>'i',
'Ï'=>'i','ï'=>'i','Ḯ'=>'I','ḯ'=>'i','Ĩ'=>'i','ĩ'=>'i','İ'=>'i','Į'=>'i','į'=>'i','Ī'=>'i','ī'=>'i',
'ỉ'=>'I','Ị'=>'I','ị'=>'i','IJ'=>'ij','ij'=>'ij','ı'=>'i',
'Ĵ'=>'j','ĵ'=>'j',
'Ķ'=>'k','ķ'=>'k','Ḵ'=>'K','ḵ'=>'k',
'Ĺ'=>'l','ĺ'=>'l','Ľ'=>'l','ľ'=>'l','Ļ'=>'l','ļ'=>'l','Ł'=>'l','ł'=>'l','Ŀ'=>'l','ŀ'=>'l',
'Ń'=>'n','ń'=>'n','Ň'=>'n','ň'=>'n','Ñ'=>'N','ñ'=>'n','Ņ'=>'n','ņ'=>'n','Ṇ'=>'N','ṇ'=>'n','Ŋ'=>'n','ŋ'=>'n',
'Ó'=>'o','ó'=>'o','Ò'=>'o','ò'=>'o','Ŏ'=>'o','ŏ'=>'o','Ô'=>'o','ô'=>'o','ố'=>'o','Ố'=>'O','ồ'=>'o',
'Ồ'=>'O','ổ'=>'o','Ổ'=>'O','Ǒ'=>'o','ǒ'=>'o','Ö'=>'o','ö'=>'o','Ő'=>'o','ő'=>'o','Õ'=>'o','õ'=>'o',
'Ø'=>'o','ø'=>'o','Ǿ'=>'o','ǿ'=>'o','Ǫ'=>'O','ǫ'=>'o','Ǭ'=>'O','ǭ'=>'o','Ō'=>'o','ō'=>'o','ỏ'=>'o',
'Ỏ'=>'O','Ơ'=>'o','ơ'=>'o','ớ'=>'o','Ớ'=>'O','ờ'=>'o','Ờ'=>'O','ở'=>'o','Ở'=>'O','ợ'=>'o','Ợ'=>'O',
'ọ'=>'o','Ọ'=>'O','ọ'=>'o','Ọ'=>'O','ộ'=>'o','Ộ'=>'O','ỗ'=>'o','Ỗ'=>'O','ỡ'=>'o','Ỡ'=>'O',
'Œ'=>'oe','œ'=>'oe',
'ĸ'=>'k',
'Ŕ'=>'r','ŕ'=>'r','Ř'=>'r','ř'=>'r','ṙ'=>'r','Ŗ'=>'r','ŗ'=>'r','Ṛ'=>'R','ṛ'=>'r','Ṟ'=>'R','ṟ'=>'r',
'S̲'=>'S','s̲'=>'s','Ś'=>'s','ś'=>'s','Ŝ'=>'s','ŝ'=>'s','Š'=>'s','š'=>'s','Ş'=>'s','ş'=>'s',
'Ṣ'=>'S','ṣ'=>'s','Ș'=>'S','ș'=>'s',
'ſ'=>'z','ß'=>'ss','Ť'=>'t','ť'=>'t','Ţ'=>'t','ţ'=>'t','Ṭ'=>'T','ṭ'=>'t','Ț'=>'T',
'ț'=>'t','Ṯ'=>'T','ṯ'=>'t','™'=>'tm','Ŧ'=>'t','ŧ'=>'t',
'Ú'=>'u','ú'=>'u','Ù'=>'u','ù'=>'u','Ŭ'=>'u','ŭ'=>'u','Û'=>'u','û'=>'u','Ǔ'=>'u','ǔ'=>'u','Ů'=>'u','ů'=>'u',
'Ü'=>'u','ü'=>'u','Ǘ'=>'u','ǘ'=>'u','Ǜ'=>'u','ǜ'=>'u','Ǚ'=>'u','ǚ'=>'u','Ǖ'=>'u','ǖ'=>'u','Ű'=>'u','ű'=>'u',
'Ũ'=>'u','ũ'=>'u','Ų'=>'u','ų'=>'u','Ū'=>'u','ū'=>'u','Ư'=>'u','ư'=>'u','ứ'=>'u','Ứ'=>'U','ừ'=>'u','Ừ'=>'U',
'ử'=>'u','Ử'=>'U','ự'=>'u','Ự'=>'U','ụ'=>'u','Ụ'=>'U','ủ'=>'u','Ủ'=>'U','ữ'=>'u','Ữ'=>'U',
'Ŵ'=>'w','ŵ'=>'w',
'Ý'=>'y','ý'=>'y','ỳ'=>'y','Ỳ'=>'Y','Ŷ'=>'y','ŷ'=>'y','ÿ'=>'y','Ÿ'=>'y','ỹ'=>'y','Ỹ'=>'Y','ỷ'=>'y','Ỷ'=>'Y',
'Z̲'=>'Z','z̲'=>'z','Ź'=>'z','ź'=>'z','Ž'=>'z','ž'=>'z','Ż'=>'z','ż'=>'z','Ẕ'=>'Z','ẕ'=>'z',
'þ'=>'p','ʼn'=>'n','А'=>'a','а'=>'a','Б'=>'b','б'=>'b','В'=>'v','в'=>'v','Г'=>'g','г'=>'g','Ґ'=>'g','ґ'=>'g',
'Д'=>'d','д'=>'d','Е'=>'e','е'=>'e','Ё'=>'jo','ё'=>'jo','Є'=>'e','є'=>'e','Ж'=>'zh','ж'=>'zh','З'=>'z','з'=>'z',
'И'=>'i','и'=>'i','І'=>'i','і'=>'i','Ї'=>'i','ї'=>'i','Й'=>'j','й'=>'j','К'=>'k','к'=>'k','Л'=>'l','л'=>'l',
'М'=>'m','м'=>'m','Н'=>'n','н'=>'n','О'=>'o','о'=>'o','П'=>'p','п'=>'p','Р'=>'r','р'=>'r','С'=>'s','с'=>'s',
'Т'=>'t','т'=>'t','У'=>'u','у'=>'u','Ф'=>'f','ф'=>'f','Х'=>'h','х'=>'h','Ц'=>'c','ц'=>'c','Ч'=>'ch','ч'=>'ch',
'Ш'=>'sh','ш'=>'sh','Щ'=>'sch','щ'=>'sch','Ъ'=>'-',
'ъ'=>'-','Ы'=>'y','ы'=>'y','Ь'=>'-','ь'=>'-',
'Э'=>'je','э'=>'je','Ю'=>'ju','ю'=>'ju','Я'=>'ja','я'=>'ja','א'=>'a','ב'=>'b','ג'=>'g','ד'=>'d','ה'=>'h','ו'=>'v',
'ז'=>'z','ח'=>'h','ט'=>'t','י'=>'i','ך'=>'k','כ'=>'k','ל'=>'l','ם'=>'m','מ'=>'m','ן'=>'n','נ'=>'n','ס'=>'s','ע'=>'e',
'ף'=>'p','פ'=>'p','ץ'=>'C','צ'=>'c','ק'=>'q','ר'=>'r','ש'=>'w','ת'=>'t'
);


$accentsRemoved = strtr( $stringToRemoveAccents , $unwanted_array );

An improved version of remove_accents() function according to last version Wordpress 4.3 formatting is:

function mbstring_binary_safe_encoding( $reset = false ) {
static $encodings = array();
static $overloaded = null;


if ( is_null( $overloaded ) )
$overloaded = function_exists( 'mb_internal_encoding' ) && ( ini_get( 'mbstring.func_overload' ) & 2 );


if ( false === $overloaded )
return;


if ( ! $reset ) {
$encoding = mb_internal_encoding();
array_push( $encodings, $encoding );
mb_internal_encoding( 'ISO-8859-1' );
}


if ( $reset && $encodings ) {
$encoding = array_pop( $encodings );
mb_internal_encoding( $encoding );
}
}


function reset_mbstring_encoding() {
mbstring_binary_safe_encoding( true );
}


function seems_utf8( $str ) {
mbstring_binary_safe_encoding();
$length = strlen($str);
reset_mbstring_encoding();
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))
return false;
}
}
return true;
}


function remove_accents( $string ) {
if ( !preg_match('/[\x80-\xff]/', $string) )
return $string;


if (seems_utf8($string)) {
$chars = array(
// Decompositions for Latin-1 Supplement
chr(194).chr(170) => 'a', chr(194).chr(186) => 'o',
chr(195).chr(128) => 'A', chr(195).chr(129) => 'A',
chr(195).chr(130) => 'A', chr(195).chr(131) => 'A',
chr(195).chr(132) => 'A', chr(195).chr(133) => 'A',
chr(195).chr(134) => 'AE',chr(195).chr(135) => 'C',
chr(195).chr(136) => 'E', chr(195).chr(137) => 'E',
chr(195).chr(138) => 'E', chr(195).chr(139) => 'E',
chr(195).chr(140) => 'I', chr(195).chr(141) => 'I',
chr(195).chr(142) => 'I', chr(195).chr(143) => 'I',
chr(195).chr(144) => 'D', chr(195).chr(145) => 'N',
chr(195).chr(146) => 'O', chr(195).chr(147) => 'O',
chr(195).chr(148) => 'O', chr(195).chr(149) => 'O',
chr(195).chr(150) => 'O', chr(195).chr(153) => 'U',
chr(195).chr(154) => 'U', chr(195).chr(155) => 'U',
chr(195).chr(156) => 'U', chr(195).chr(157) => 'Y',
chr(195).chr(158) => 'TH',chr(195).chr(159) => 's',
chr(195).chr(160) => 'a', chr(195).chr(161) => 'a',
chr(195).chr(162) => 'a', chr(195).chr(163) => 'a',
chr(195).chr(164) => 'a', chr(195).chr(165) => 'a',
chr(195).chr(166) => 'ae',chr(195).chr(167) => 'c',
chr(195).chr(168) => 'e', chr(195).chr(169) => 'e',
chr(195).chr(170) => 'e', chr(195).chr(171) => 'e',
chr(195).chr(172) => 'i', chr(195).chr(173) => 'i',
chr(195).chr(174) => 'i', chr(195).chr(175) => 'i',
chr(195).chr(176) => 'd', chr(195).chr(177) => 'n',
chr(195).chr(178) => 'o', chr(195).chr(179) => 'o',
chr(195).chr(180) => 'o', chr(195).chr(181) => 'o',
chr(195).chr(182) => 'o', chr(195).chr(184) => 'o',
chr(195).chr(185) => 'u', chr(195).chr(186) => 'u',
chr(195).chr(187) => 'u', chr(195).chr(188) => 'u',
chr(195).chr(189) => 'y', chr(195).chr(190) => 'th',
chr(195).chr(191) => 'y', chr(195).chr(152) => 'O',
// Decompositions for Latin Extended-A
chr(196).chr(128) => 'A', chr(196).chr(129) => 'a',
chr(196).chr(130) => 'A', chr(196).chr(131) => 'a',
chr(196).chr(132) => 'A', chr(196).chr(133) => 'a',
chr(196).chr(134) => 'C', chr(196).chr(135) => 'c',
chr(196).chr(136) => 'C', chr(196).chr(137) => 'c',
chr(196).chr(138) => 'C', chr(196).chr(139) => 'c',
chr(196).chr(140) => 'C', chr(196).chr(141) => 'c',
chr(196).chr(142) => 'D', chr(196).chr(143) => 'd',
chr(196).chr(144) => 'D', chr(196).chr(145) => 'd',
chr(196).chr(146) => 'E', chr(196).chr(147) => 'e',
chr(196).chr(148) => 'E', chr(196).chr(149) => 'e',
chr(196).chr(150) => 'E', chr(196).chr(151) => 'e',
chr(196).chr(152) => 'E', chr(196).chr(153) => 'e',
chr(196).chr(154) => 'E', chr(196).chr(155) => 'e',
chr(196).chr(156) => 'G', chr(196).chr(157) => 'g',
chr(196).chr(158) => 'G', chr(196).chr(159) => 'g',
chr(196).chr(160) => 'G', chr(196).chr(161) => 'g',
chr(196).chr(162) => 'G', chr(196).chr(163) => 'g',
chr(196).chr(164) => 'H', chr(196).chr(165) => 'h',
chr(196).chr(166) => 'H', chr(196).chr(167) => 'h',
chr(196).chr(168) => 'I', chr(196).chr(169) => 'i',
chr(196).chr(170) => 'I', chr(196).chr(171) => 'i',
chr(196).chr(172) => 'I', chr(196).chr(173) => 'i',
chr(196).chr(174) => 'I', chr(196).chr(175) => 'i',
chr(196).chr(176) => 'I', chr(196).chr(177) => 'i',
chr(196).chr(178) => 'IJ',chr(196).chr(179) => 'ij',
chr(196).chr(180) => 'J', chr(196).chr(181) => 'j',
chr(196).chr(182) => 'K', chr(196).chr(183) => 'k',
chr(196).chr(184) => 'k', chr(196).chr(185) => 'L',
chr(196).chr(186) => 'l', chr(196).chr(187) => 'L',
chr(196).chr(188) => 'l', chr(196).chr(189) => 'L',
chr(196).chr(190) => 'l', chr(196).chr(191) => 'L',
chr(197).chr(128) => 'l', chr(197).chr(129) => 'L',
chr(197).chr(130) => 'l', chr(197).chr(131) => 'N',
chr(197).chr(132) => 'n', chr(197).chr(133) => 'N',
chr(197).chr(134) => 'n', chr(197).chr(135) => 'N',
chr(197).chr(136) => 'n', chr(197).chr(137) => 'N',
chr(197).chr(138) => 'n', chr(197).chr(139) => 'N',
chr(197).chr(140) => 'O', chr(197).chr(141) => 'o',
chr(197).chr(142) => 'O', chr(197).chr(143) => 'o',
chr(197).chr(144) => 'O', chr(197).chr(145) => 'o',
chr(197).chr(146) => 'OE',chr(197).chr(147) => 'oe',
chr(197).chr(148) => 'R',chr(197).chr(149) => 'r',
chr(197).chr(150) => 'R',chr(197).chr(151) => 'r',
chr(197).chr(152) => 'R',chr(197).chr(153) => 'r',
chr(197).chr(154) => 'S',chr(197).chr(155) => 's',
chr(197).chr(156) => 'S',chr(197).chr(157) => 's',
chr(197).chr(158) => 'S',chr(197).chr(159) => 's',
chr(197).chr(160) => 'S', chr(197).chr(161) => 's',
chr(197).chr(162) => 'T', chr(197).chr(163) => 't',
chr(197).chr(164) => 'T', chr(197).chr(165) => 't',
chr(197).chr(166) => 'T', chr(197).chr(167) => 't',
chr(197).chr(168) => 'U', chr(197).chr(169) => 'u',
chr(197).chr(170) => 'U', chr(197).chr(171) => 'u',
chr(197).chr(172) => 'U', chr(197).chr(173) => 'u',
chr(197).chr(174) => 'U', chr(197).chr(175) => 'u',
chr(197).chr(176) => 'U', chr(197).chr(177) => 'u',
chr(197).chr(178) => 'U', chr(197).chr(179) => 'u',
chr(197).chr(180) => 'W', chr(197).chr(181) => 'w',
chr(197).chr(182) => 'Y', chr(197).chr(183) => 'y',
chr(197).chr(184) => 'Y', chr(197).chr(185) => 'Z',
chr(197).chr(186) => 'z', chr(197).chr(187) => 'Z',
chr(197).chr(188) => 'z', chr(197).chr(189) => 'Z',
chr(197).chr(190) => 'z', chr(197).chr(191) => 's',
// Decompositions for Latin Extended-B
chr(200).chr(152) => 'S', chr(200).chr(153) => 's',
chr(200).chr(154) => 'T', chr(200).chr(155) => 't',
// Euro Sign
chr(226).chr(130).chr(172) => 'E',
// GBP (Pound) Sign
chr(194).chr(163) => '',
// Vowels with diacritic (Vietnamese)
// unmarked
chr(198).chr(160) => 'O', chr(198).chr(161) => 'o',
chr(198).chr(175) => 'U', chr(198).chr(176) => 'u',
// grave accent
chr(225).chr(186).chr(166) => 'A', chr(225).chr(186).chr(167) => 'a',
chr(225).chr(186).chr(176) => 'A', chr(225).chr(186).chr(177) => 'a',
chr(225).chr(187).chr(128) => 'E', chr(225).chr(187).chr(129) => 'e',
chr(225).chr(187).chr(146) => 'O', chr(225).chr(187).chr(147) => 'o',
chr(225).chr(187).chr(156) => 'O', chr(225).chr(187).chr(157) => 'o',
chr(225).chr(187).chr(170) => 'U', chr(225).chr(187).chr(171) => 'u',
chr(225).chr(187).chr(178) => 'Y', chr(225).chr(187).chr(179) => 'y',
// hook
chr(225).chr(186).chr(162) => 'A', chr(225).chr(186).chr(163) => 'a',
chr(225).chr(186).chr(168) => 'A', chr(225).chr(186).chr(169) => 'a',
chr(225).chr(186).chr(178) => 'A', chr(225).chr(186).chr(179) => 'a',
chr(225).chr(186).chr(186) => 'E', chr(225).chr(186).chr(187) => 'e',
chr(225).chr(187).chr(130) => 'E', chr(225).chr(187).chr(131) => 'e',
chr(225).chr(187).chr(136) => 'I', chr(225).chr(187).chr(137) => 'i',
chr(225).chr(187).chr(142) => 'O', chr(225).chr(187).chr(143) => 'o',
chr(225).chr(187).chr(148) => 'O', chr(225).chr(187).chr(149) => 'o',
chr(225).chr(187).chr(158) => 'O', chr(225).chr(187).chr(159) => 'o',
chr(225).chr(187).chr(166) => 'U', chr(225).chr(187).chr(167) => 'u',
chr(225).chr(187).chr(172) => 'U', chr(225).chr(187).chr(173) => 'u',
chr(225).chr(187).chr(182) => 'Y', chr(225).chr(187).chr(183) => 'y',
// tilde
chr(225).chr(186).chr(170) => 'A', chr(225).chr(186).chr(171) => 'a',
chr(225).chr(186).chr(180) => 'A', chr(225).chr(186).chr(181) => 'a',
chr(225).chr(186).chr(188) => 'E', chr(225).chr(186).chr(189) => 'e',
chr(225).chr(187).chr(132) => 'E', chr(225).chr(187).chr(133) => 'e',
chr(225).chr(187).chr(150) => 'O', chr(225).chr(187).chr(151) => 'o',
chr(225).chr(187).chr(160) => 'O', chr(225).chr(187).chr(161) => 'o',
chr(225).chr(187).chr(174) => 'U', chr(225).chr(187).chr(175) => 'u',
chr(225).chr(187).chr(184) => 'Y', chr(225).chr(187).chr(185) => 'y',
// acute accent
chr(225).chr(186).chr(164) => 'A', chr(225).chr(186).chr(165) => 'a',
chr(225).chr(186).chr(174) => 'A', chr(225).chr(186).chr(175) => 'a',
chr(225).chr(186).chr(190) => 'E', chr(225).chr(186).chr(191) => 'e',
chr(225).chr(187).chr(144) => 'O', chr(225).chr(187).chr(145) => 'o',
chr(225).chr(187).chr(154) => 'O', chr(225).chr(187).chr(155) => 'o',
chr(225).chr(187).chr(168) => 'U', chr(225).chr(187).chr(169) => 'u',
// dot below
chr(225).chr(186).chr(160) => 'A', chr(225).chr(186).chr(161) => 'a',
chr(225).chr(186).chr(172) => 'A', chr(225).chr(186).chr(173) => 'a',
chr(225).chr(186).chr(182) => 'A', chr(225).chr(186).chr(183) => 'a',
chr(225).chr(186).chr(184) => 'E', chr(225).chr(186).chr(185) => 'e',
chr(225).chr(187).chr(134) => 'E', chr(225).chr(187).chr(135) => 'e',
chr(225).chr(187).chr(138) => 'I', chr(225).chr(187).chr(139) => 'i',
chr(225).chr(187).chr(140) => 'O', chr(225).chr(187).chr(141) => 'o',
chr(225).chr(187).chr(152) => 'O', chr(225).chr(187).chr(153) => 'o',
chr(225).chr(187).chr(162) => 'O', chr(225).chr(187).chr(163) => 'o',
chr(225).chr(187).chr(164) => 'U', chr(225).chr(187).chr(165) => 'u',
chr(225).chr(187).chr(176) => 'U', chr(225).chr(187).chr(177) => 'u',
chr(225).chr(187).chr(180) => 'Y', chr(225).chr(187).chr(181) => 'y',
// Vowels with diacritic (Chinese, Hanyu Pinyin)
chr(201).chr(145) => 'a',
// macron
chr(199).chr(149) => 'U', chr(199).chr(150) => 'u',
// acute accent
chr(199).chr(151) => 'U', chr(199).chr(152) => 'u',
// caron
chr(199).chr(141) => 'A', chr(199).chr(142) => 'a',
chr(199).chr(143) => 'I', chr(199).chr(144) => 'i',
chr(199).chr(145) => 'O', chr(199).chr(146) => 'o',
chr(199).chr(147) => 'U', chr(199).chr(148) => 'u',
chr(199).chr(153) => 'U', chr(199).chr(154) => 'u',
// grave accent
chr(199).chr(155) => 'U', chr(199).chr(156) => 'u',
);


$string = strtr($string, $chars);
} else {
$chars = array();
// Assume ISO-8859-1 if not UTF-8
$chars['in'] = chr(128).chr(131).chr(138).chr(142).chr(154).chr(158)
.chr(159).chr(162).chr(165).chr(181).chr(192).chr(193).chr(194)
.chr(195).chr(196).chr(197).chr(199).chr(200).chr(201).chr(202)
.chr(203).chr(204).chr(205).chr(206).chr(207).chr(209).chr(210)
.chr(211).chr(212).chr(213).chr(214).chr(216).chr(217).chr(218)
.chr(219).chr(220).chr(221).chr(224).chr(225).chr(226).chr(227)
.chr(228).chr(229).chr(231).chr(232).chr(233).chr(234).chr(235)
.chr(236).chr(237).chr(238).chr(239).chr(241).chr(242).chr(243)
.chr(244).chr(245).chr(246).chr(248).chr(249).chr(250).chr(251)
.chr(252).chr(253).chr(255);


$chars['out'] = "EfSZszYcYuAAAAAACEEEEIIIINOOOOOOUUUUYaaaaaaceeeeiiiinoooooouuuuyy";


$string = strtr($string, $chars['in'], $chars['out']);
$double_chars = array();
$double_chars['in'] = array(chr(140), chr(156), chr(198), chr(208), chr(222), chr(223), chr(230), chr(240), chr(254));
$double_chars['out'] = array('OE', 'oe', 'AE', 'DH', 'TH', 'ss', 'ae', 'dh', 'th');
$string = str_replace($double_chars['in'], $double_chars['out'], $string);
}


return $string;
}

My answer is an update of @dynamic solution since Romanian or perhaps other language diacritics weren't converted. I wrote the minimum functions and works like a charm.

print_r(remove_accents('Iași, Iași County, Romania'));

here is a simple function that i use usually to remove accents :

function str_without_accents($str, $charset='utf-8')
{
$str = htmlentities($str, ENT_NOQUOTES, $charset);


$str = preg_replace('#&([A-za-z])(?:acute|cedil|caron|circ|grave|orn|ring|slash|th|tilde|uml);#', '\1', $str);
$str = preg_replace('#&([A-za-z]{2})(?:lig);#', '\1', $str); // pour les ligatures e.g. '&oelig;'
$str = preg_replace('#&[^;]+;#', '', $str); // supprime les autres caractères


return $str;   // or add this : mb_strtoupper($str); for uppercase :)
}
<?php
/*
* Thanks:
*   - The idea of extracting accents equiv chars with the help of the HTMLSpecialChars convertion was taking from ICanBoogie Package of 'Olivier Laviale' {@link http://www.weirdog.com/blog/php/supprimer-les-accents-des-caracteres-accentues.html}
*/
function accentCharsModifier($str){
if(($length=mb_strlen($str,"UTF-8"))<strlen($str)){
$i=$count=0;
while($i<$length){
if(strlen($c=mb_substr($str,$i,1,"UTF-8"))>1){
$he=htmlentities($c);
if(($nC=preg_replace("#&([A-Za-z])(?:acute|cedil|caron|circ|grave|orn|ring|slash|th|tilde|uml);#", "\\1", $he))!=$he ||
($nC=preg_replace("#&([A-Za-z]{2})(?:lig);#", "\\1", $he))!=$he ||
($nC=preg_replace("#&[^;]+;#", "", $he))!=$he){
$str=str_replace($c,$nC,$str,$count);if($nC==""){$length=$length-$count;$i--;}
}
}
$i++;
}
}
return $str;
}
echo accentCharsModifier("&éôpkAÈû");
?>

I just created a removeAccents method based on the reading of this thread and this other one too (How to remove accents and turn letters into "plain" ASCII characters?).

The method is here: https://github.com/lingtalfi/Bat/blob/master/StringTool.md#removeaccents

Tests are here: https://github.com/lingtalfi/Bat/blob/master/btests/StringTool/removeAccents/stringTool.removeAccents.test.php,

and here is what was tested so far:

$a = [
// easy
'',
'a',
'après',
'dédé fait la fête ?',
// hard
'àáâãäçèéêëìíîïñòóôõöùúûüýÿÀÁÂÃÄÇÈÉÊËÌÍÎÏÑÒÓÔÕÖÙÚÛÜÝ',
'ŻŹĆŃĄŚŁĘÓżźćńąśłęó',
'qqqqŻŹĆŃĄŚŁĘÓżźćńąśłęóqqq',
'ŠŽšžŸÀÁÂÃÄÅÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝàáâãäåçèéêëìíîïðñòóôõöøùúûüýÿ',
'ÀÁÂÃÄÅÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖØÙÚÛÜÝàáâãäåçèéêëìíîïñòóôõöøùúûüýÿ',
'ĀāĂ㥹ĆćĈĉĊċČčĎďĐđĒēĔĕĖėĘęĚěĜĝĞğĠġĢģĤĥĦħĨĩĪīĬĭĮįİĴĵĶķ',
'ĹĺĻļĽľĿŀŁłŃńŅņŇňʼnŌōŎŏŐőŔŕŖŗŘřŚśŜŝŞşŠšŢţŤťŦŧŨũŪūŬŭŮůŰűŲųŴŵŶŷŸŹźŻżŽž',
'ſƒƠơƯưǍǎǏǐǑǒǓǔǕǖǗǘǙǚǛǜǺǻǾǿ',
'Ǽǽ',
];

and it converts only accentuated things (letters/ligatures/cédilles/some letters with a line through/...?).

Here is the content of the method: (https://github.com/lingtalfi/Bat/blob/master/StringTool.php#L83)

public static function removeAccents($str)
{
static $map = [
// single letters
'à' => 'a',
'á' => 'a',
'â' => 'a',
'ã' => 'a',
'ä' => 'a',
'ą' => 'a',
'å' => 'a',
'ā' => 'a',
'ă' => 'a',
'ǎ' => 'a',
'ǻ' => 'a',
'À' => 'A',
'Á' => 'A',
'Â' => 'A',
'Ã' => 'A',
'Ä' => 'A',
'Ą' => 'A',
'Å' => 'A',
'Ā' => 'A',
'Ă' => 'A',
'Ǎ' => 'A',
'Ǻ' => 'A',




'ç' => 'c',
'ć' => 'c',
'ĉ' => 'c',
'ċ' => 'c',
'č' => 'c',
'Ç' => 'C',
'Ć' => 'C',
'Ĉ' => 'C',
'Ċ' => 'C',
'Č' => 'C',


'ď' => 'd',
'đ' => 'd',
'Ð' => 'D',
'Ď' => 'D',
'Đ' => 'D',




'è' => 'e',
'é' => 'e',
'ê' => 'e',
'ë' => 'e',
'ę' => 'e',
'ē' => 'e',
'ĕ' => 'e',
'ė' => 'e',
'ě' => 'e',
'È' => 'E',
'É' => 'E',
'Ê' => 'E',
'Ë' => 'E',
'Ę' => 'E',
'Ē' => 'E',
'Ĕ' => 'E',
'Ė' => 'E',
'Ě' => 'E',


'ƒ' => 'f',




'ĝ' => 'g',
'ğ' => 'g',
'ġ' => 'g',
'ģ' => 'g',
'Ĝ' => 'G',
'Ğ' => 'G',
'Ġ' => 'G',
'Ģ' => 'G',




'ĥ' => 'h',
'ħ' => 'h',
'Ĥ' => 'H',
'Ħ' => 'H',


'ì' => 'i',
'í' => 'i',
'î' => 'i',
'ï' => 'i',
'ĩ' => 'i',
'ī' => 'i',
'ĭ' => 'i',
'į' => 'i',
'ſ' => 'i',
'ǐ' => 'i',
'Ì' => 'I',
'Í' => 'I',
'Î' => 'I',
'Ï' => 'I',
'Ĩ' => 'I',
'Ī' => 'I',
'Ĭ' => 'I',
'Į' => 'I',
'İ' => 'I',
'Ǐ' => 'I',


'ĵ' => 'j',
'Ĵ' => 'J',


'ķ' => 'k',
'Ķ' => 'K',




'ł' => 'l',
'ĺ' => 'l',
'ļ' => 'l',
'ľ' => 'l',
'ŀ' => 'l',
'Ł' => 'L',
'Ĺ' => 'L',
'Ļ' => 'L',
'Ľ' => 'L',
'Ŀ' => 'L',




'ñ' => 'n',
'ń' => 'n',
'ņ' => 'n',
'ň' => 'n',
'ʼn' => 'n',
'Ñ' => 'N',
'Ń' => 'N',
'Ņ' => 'N',
'Ň' => 'N',


'ò' => 'o',
'ó' => 'o',
'ô' => 'o',
'õ' => 'o',
'ö' => 'o',
'ð' => 'o',
'ø' => 'o',
'ō' => 'o',
'ŏ' => 'o',
'ő' => 'o',
'ơ' => 'o',
'ǒ' => 'o',
'ǿ' => 'o',
'Ò' => 'O',
'Ó' => 'O',
'Ô' => 'O',
'Õ' => 'O',
'Ö' => 'O',
'Ø' => 'O',
'Ō' => 'O',
'Ŏ' => 'O',
'Ő' => 'O',
'Ơ' => 'O',
'Ǒ' => 'O',
'Ǿ' => 'O',




'ŕ' => 'r',
'ŗ' => 'r',
'ř' => 'r',
'Ŕ' => 'R',
'Ŗ' => 'R',
'Ř' => 'R',




'ś' => 's',
'š' => 's',
'ŝ' => 's',
'ş' => 's',
'Ś' => 'S',
'Š' => 'S',
'Ŝ' => 'S',
'Ş' => 'S',


'ţ' => 't',
'ť' => 't',
'ŧ' => 't',
'Ţ' => 'T',
'Ť' => 'T',
'Ŧ' => 'T',




'ù' => 'u',
'ú' => 'u',
'û' => 'u',
'ü' => 'u',
'ũ' => 'u',
'ū' => 'u',
'ŭ' => 'u',
'ů' => 'u',
'ű' => 'u',
'ų' => 'u',
'ư' => 'u',
'ǔ' => 'u',
'ǖ' => 'u',
'ǘ' => 'u',
'ǚ' => 'u',
'ǜ' => 'u',
'Ù' => 'U',
'Ú' => 'U',
'Û' => 'U',
'Ü' => 'U',
'Ũ' => 'U',
'Ū' => 'U',
'Ŭ' => 'U',
'Ů' => 'U',
'Ű' => 'U',
'Ų' => 'U',
'Ư' => 'U',
'Ǔ' => 'U',
'Ǖ' => 'U',
'Ǘ' => 'U',
'Ǚ' => 'U',
'Ǜ' => 'U',




'ŵ' => 'w',
'Ŵ' => 'W',


'ý' => 'y',
'ÿ' => 'y',
'ŷ' => 'y',
'Ý' => 'Y',
'Ÿ' => 'Y',
'Ŷ' => 'Y',


'ż' => 'z',
'ź' => 'z',
'ž' => 'z',
'Ż' => 'Z',
'Ź' => 'Z',
'Ž' => 'Z',




// accentuated ligatures
'Ǽ' => 'A',
'ǽ' => 'a',
];
return strtr($str, $map);
}

if you have http://php.net/manual/en/book.intl.php available, this solved your problem

$string = "Fóø Bår";
$transliterator = Transliterator::createFromRules(':: Any-Latin; :: Latin-ASCII; :: NFD; :: [:Nonspacing Mark:] Remove; :: Lower(); :: NFC;', Transliterator::FORWARD);
echo $normalized = $transliterator->transliterate($string);

Based on @Mimouni answer I made this function to transliterate Accented strings to Non Accented strings.

/**
* @param $str Convert string to lowercase and replace special chars to equivalents ou remove its
* @return string
*/
function _slugify(string $string): string
{
$str = $string; // for comparisons
$str = _toUtf8($str); // Force to work with string in UTF-8
$str = iconv('UTF-8', 'ASCII//TRANSLIT', $str);


if ($str != htmlentities($string, ENT_QUOTES, 'UTF-8')) { // iconv fails
$str = _toUtf8($string);
$str = htmlentities($str, ENT_QUOTES, 'UTF-8');
$str = preg_replace('#&([a-z]{1,2})(acute|cedil|circ|grave|lig|orn|ring|slash|th|tilde|uml);#i', '$1', $str);
// Need to strip non ASCII chars or any other than a-z, A-Z, 0-9...
$str = html_entity_decode($str, ENT_QUOTES, 'UTF-8');
$str = preg_replace(array('#[^0-9a-z]#i', '#[ -]+#'), ' ', $str);
$str = trim($str, ' -');
}


// lowercase
$string = strtolower($str);


return $string;
}

To convert strings to UTF-8, here I use the Multi Byte String extension. Note that I break string in pieces to avoid trouble with mixed content (I have such situation) and convert word by word.

/**
* @param $str string String in any encoding
* @return string
*/
function _toUtf8(string $str_in): ?string
{
if (!function_exists('mb_detect_encoding')) {
throw new \Exception('The Multi Byte String extension is absent!');
}
$str_out = [];
$words = explode(" ", $str_in);
foreach ($words as $word) {
$current_encoding = mb_detect_encoding($word, 'UTF-8, ASCII, ISO-8859-1');
$str_out[] = mb_convert_encoding($word, 'UTF-8', $current_encoding);
}
return implode(" ", $str_out);
}

Footer Notes: Was the only solution that pass in PHPUnit UnitTests in Windows command Line (locale issues) The @gabo solution should work but unfortunately not for me

In laravel you can simply use str_slug($accentedPhrase) and if you care about dash (-) that this method substitute with space you can use str_replace('-', ' ', str_slug($accentedPhrase))

Something like this?

$arrSearch  = explode(","," ,ç,æ, œ, á,é,í,ó,ú,à,è,ì,ò,ù,ä,ë,ï,ö,ü,ÿ,â,ê,î,ô,û,å,e,i,ø,u");


$arrReplace = explode(",","_,c,ae,oe,a,e,i,o,u,a,e,i,o,u,a,e,i,o,u,y,a,e,i,o,u,a,e,i,o,u");


$output = str_replace($arrSearch, $arrReplace, $input);

If the main task is just to use the string in a URL, why not to use slugyfier?

composer require cocur/slugify

then

use Cocur\Slugify\Slugify;


$slugify = new Slugify();
echo $slugify->slugify('Fóø Bår');

It also has many bridges for popular frameworks. E.g. you can use Doctrine Extensions Sluggable behaviour to generate automatically unique slug for each entity in DB and use it in URL.

If you want just to wipe out all accents you can play around with rulesets to satisfy the requirements.

What's wrong with this one? Works with UTF8

function strip_accents($s){
return str_replace(
explode(' ', preg_replace('/ +/', ' ', 'č ć ž š đ  Č Ć Ž Š Đ  à á â ã ä ç è é ê ë ì í î ï ñ ò ó ô õ ö ù ú û ü ý ÿ À Á Â Ã Ä Ç È É Ê Ë Ì Í Î Ï Ñ Ò Ó Ô Õ Ö Ù Ú Û Ü Ý')),
explode(' ', preg_replace('/ +/', ' ', 'c c z s dj C C Z S DJ a a a a a c e e e e i i i i n o o o o o u u u u y y A A A A A C E E E E I I I I N O O O O O U U U U Y')),
$s);
}

It can be faster by not using preg_replace, but speed was not my goal here.

This answer I've got following tips here, so it is not really mine. It works for me using LATIN1 or UTF-8. If you use other charsets, you probably should add them to mb_detect_encoding function. Correct environment set is probably needed also.

function NoAccents($s){
return iconv(mb_detect_encoding($s,'UTF-8, ASCII, ISO-8859-1'),'ASCII//TRANSLIT//INGORE',$s);
}

Combining some of the answers:

/**
* Given an utf8 string, returns an ascii string.
* Only supports ISO-8859-1 chars, not chars like č, œ, Œ, ř, Š, š, ů, Ÿ or ž
* @param string $utf8
* @return string ascii
*/
function stripAccents(string $utf8): string
{
$src = 'àáâãäåçèéêëìíîïñòóôõöùúûüýÿÀÁÂÃÄÇÈÉÊËÌÍÎÏÑÒÓÔÕÖÙÚÛÜÝ';
$dst = 'aaaaaaceeeeiiiinooooouuuuyyAAAAACEEEEIIIINOOOOOUUUUY';
$iso8859_1 = strtr(
utf8_decode($utf8),
utf8_decode($src),
$dst
);
// iconv below not used for UTF-8 directly because it adds chars like ^'"`
// which are nice to not lose info, but not very readable and not compatible with filenames
// iconv() additionally converts chars like
// ¡ ¢ £  ¥   ¦ §  ¨  ©  ª «  ¬   SHY ®    °  ±   ²  ³  ´ µ ¶ · ¸ ¹  º »  ¼   ½   ¾   ¿ Å Æ  Ð Ø Þ  ß  æ  ÷   ø þ
// ! c lb yen | SS " (c) a << not SHY (R)  ^0 +/- ^2 ^3 ' u P . , ^1 o >> 1/4 1/2 3/4 ? A AE D O Th ss ae d : o th
return iconv('ISO-8859-1', 'ASCII//TRANSLIT//IGNORE', $iso8859_1);
}
function Unaccent($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'));
}