utf8_encode

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

utf8_encode — 将字符串从 ISO-8859-1 转换为 UTF-8 编码

警告

此函数自 PHP 8.2.0 起弃用。强烈建议不要应用此函数。

说明

#[\Deprecated]
function utf8_encode(string $string): string

该函数将 string 字符串从 ISO-8859-1 编码转换为 UTF-8。

注意:
This function does not attempt to guess the current encoding of the provided string, it assumes it is encoded as ISO-8859-1 (also known as "Latin 1") and converts to UTF-8. Since every sequence of bytes is a valid ISO-8859-1 string, this never results in an error, but will not result in a useful string if a different encoding was intended.

Many web pages marked as using the ISO-8859-1 character encoding actually use the similar Windows-1252 encoding, and web browsers will interpret ISO-8859-1 web pages as Windows-1252. Windows-1252 features additional printable characters, such as the Euro sign (€) and curly quotes (" "), instead of certain ISO-8859-1 control characters. This function will not convert such Windows-1252 characters correctly. Use a different function if Windows-1252 conversion is required.

参数

string: ISO-8859-1 字符串。

返回值

返回 string 的 UTF-8 翻译。

更新日志

版本	说明
8.2.0	弃用此函数。
7.2.0	This function has been moved from the XML extension to the core of PHP. In previous versions, it was only available if the XML extension was installed.

示例

示例 #1 基础示例

<?php
// Convert the string 'Zoë' from ISO 8859-1 to UTF-8
$iso8859_1_string = "\x5A\x6F\xEB";
$utf8_string = utf8_encode($iso8859_1_string);
echo bin2hex($utf8_string), "\n";
?>

以上示例会输出:

5a6fc3ab

注释

注意: 弃用和替代方案

从 PHP 8.2.0 开始,弃用此函数,并将在未来的版本中删除。应检查现有用途并用适当的替代方案。

类似的功能可以通过 mb_convert_encoding() 实现,支持 ISO-8859-1 和许多其他字符编码。

<?php
$iso8859_1_string = "\xEB"; // 'ë' (e with diaeresis) in ISO-8859-1
$utf8_string = mb_convert_encoding($iso8859_1_string, 'UTF-8', 'ISO-8859-1');
echo bin2hex($utf8_string), "\n";
$iso8859_7_string = "\xEB"; // the same string in ISO-8859-7 represents 'λ' (Greek lower-case lambda)
$utf8_string = mb_convert_encoding($iso8859_7_string, 'UTF-8', 'ISO-8859-7');
echo bin2hex($utf8_string), "\n";
$windows_1252_string = "\x80"; // '€' (Euro sign) in Windows-1252, but not in ISO-8859-1
$utf8_string = mb_convert_encoding($windows_1252_string, 'UTF-8', 'Windows-1252');
echo bin2hex($utf8_string), "\n";
?>

以上示例会输出:

c3ab
cebb
e282ac

根据安装的扩展,其他有效选项是 UConverter::transcode() 和 iconv() 。

以下都给出相同的结果:

<?php
$iso8859_1_string = "\x5A\x6F\xEB"; // 'Zoë' in ISO-8859-1
$utf8_string = utf8_encode($iso8859_1_string);
echo bin2hex($utf8_string), "\n";
$utf8_string = mb_convert_encoding($iso8859_1_string, 'UTF-8', 'ISO-8859-1');
echo bin2hex($utf8_string), "\n";
$utf8_string = UConverter::transcode($iso8859_1_string, 'UTF8', 'ISO-8859-1');
echo bin2hex($utf8_string), "\n";
$utf8_string = iconv('ISO-8859-1', 'UTF-8', $iso8859_1_string);
echo bin2hex($utf8_string), "\n";
?>

以上示例会输出:

5a6fc3ab
5a6fc3ab
5a6fc3ab
5a6fc3ab

参见

utf8_decode() - 将字符串从 UTF-8 转换为 ISO-8859-1,替换无效或者无法表示的字符。
mb_convert_encoding() - 转换字符串,从一个字符编码到另一个字符编码
UConverter::transcode() - Convert a string from one character encoding to another
iconv() - 将字符串从一个字符编码转换到另一个字符编码

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用户贡献的备注 3 notes

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139

deceze at gmail dot com ¶

14 years ago

Please note that utf8_encode only converts a string encoded in ISO-8859-1 to UTF-8. A more appropriate name for it would be "iso88591_to_utf8". If your text is not encoded in ISO-8859-1, you do not need this function. If your text is already in UTF-8, you do not need this function. In fact, applying this function to text that is not encoded in ISO-8859-1 will most likely simply garble that text.
If you need to convert text from any encoding to any other encoding, look at iconv() instead.

down

Aidan Kehoe <php-manual at parhasard dot net> ¶

21 years ago

Here's some code that addresses the issue that Steven describes in the previous comment; 
<?php
/* This structure encodes the difference between ISO-8859-1 and Windows-1252,
 as a map from the UTF-8 encoding of some ISO-8859-1 control characters to
 the UTF-8 encoding of the non-control characters that Windows-1252 places
 at the equivalent code points. */
$cp1252_map = array(
 "\xc2\x80" => "\xe2\x82\xac", /* EURO SIGN */
 "\xc2\x82" => "\xe2\x80\x9a", /* SINGLE LOW-9 QUOTATION MARK */
 "\xc2\x83" => "\xc6\x92", /* LATIN SMALL LETTER F WITH HOOK */
 "\xc2\x84" => "\xe2\x80\x9e", /* DOUBLE LOW-9 QUOTATION MARK */
 "\xc2\x85" => "\xe2\x80\xa6", /* HORIZONTAL ELLIPSIS */
 "\xc2\x86" => "\xe2\x80\xa0", /* DAGGER */
 "\xc2\x87" => "\xe2\x80\xa1", /* DOUBLE DAGGER */
 "\xc2\x88" => "\xcb\x86", /* MODIFIER LETTER CIRCUMFLEX ACCENT */
 "\xc2\x89" => "\xe2\x80\xb0", /* PER MILLE SIGN */
 "\xc2\x8a" => "\xc5\xa0", /* LATIN CAPITAL LETTER S WITH CARON */
 "\xc2\x8b" => "\xe2\x80\xb9", /* SINGLE LEFT-POINTING ANGLE QUOTATION */
 "\xc2\x8c" => "\xc5\x92", /* LATIN CAPITAL LIGATURE OE */
 "\xc2\x8e" => "\xc5\xbd", /* LATIN CAPITAL LETTER Z WITH CARON */
 "\xc2\x91" => "\xe2\x80\x98", /* LEFT SINGLE QUOTATION MARK */
 "\xc2\x92" => "\xe2\x80\x99", /* RIGHT SINGLE QUOTATION MARK */
 "\xc2\x93" => "\xe2\x80\x9c", /* LEFT DOUBLE QUOTATION MARK */
 "\xc2\x94" => "\xe2\x80\x9d", /* RIGHT DOUBLE QUOTATION MARK */
 "\xc2\x95" => "\xe2\x80\xa2", /* BULLET */
 "\xc2\x96" => "\xe2\x80\x93", /* EN DASH */
 "\xc2\x97" => "\xe2\x80\x94", /* EM DASH */
 "\xc2\x98" => "\xcb\x9c", /* SMALL TILDE */
 "\xc2\x99" => "\xe2\x84\xa2", /* TRADE MARK SIGN */
 "\xc2\x9a" => "\xc5\xa1", /* LATIN SMALL LETTER S WITH CARON */
 "\xc2\x9b" => "\xe2\x80\xba", /* SINGLE RIGHT-POINTING ANGLE QUOTATION*/
 "\xc2\x9c" => "\xc5\x93", /* LATIN SMALL LIGATURE OE */
 "\xc2\x9e" => "\xc5\xbe", /* LATIN SMALL LETTER Z WITH CARON */
 "\xc2\x9f" => "\xc5\xb8" /* LATIN CAPITAL LETTER Y WITH DIAERESIS*/
);
function cp1252_to_utf8($str) {
 global $cp1252_map; 
 return strtr(utf8_encode($str), $cp1252_map);
}
?>

down

Mark AT modernbill DOT com ¶

21 years ago

If you haven't guessed already: If the UTF-8 character has no representation in the ISO-8859-1 codepage, a ? will be returned. You might want to wrap a function around this to make sure you aren't saving a bunch of ???? into your database.