问题
I heard PHP has very poor Unicode support. So what does it take to make a PHP 5 built application Unicode supported under PHP 5.3+? Would mbstring be the only option here? How has Facebook or Yahoo gotten around this PHP limitation?
回答1:
PHP has no low-level support for any encoding. But all that actually means is that it doesn't care on a language level. Strings in PHP are raw byte sequences, which can be in any encoding you like. When handling multi-byte strings, you need to take care to use the right string manipulation function instead of possibly screwing with the byte stream directly. So the only "non-support" of Unicode is that it doesn't include the concept of encodings into the core language itself, but you can still work with any encoding perfectly fine by manipulating strings using the appropriate string function.
Actually, if you just take a little care to keep everything in UTF-8 all the time, you will rarely have to worry about anything regarding encodings. PHP works just fine with Unicode.
For extensive coverage of this topic, please see What Every Programmer Absolutely, Positively Needs To Know About Encodings And Character Sets To Work With Text.
回答2:
PHP has poor Unicode support, but it's not impossible to do it, you just have to be careful with the functions you are using and their support for unicode. This page has a good summary of unicode support for the different functions and extensions http://www.phpwact.org/php/i18n/utf-8
回答3:
If the data comes from a tables that use UTF-8 you should just set the correct headers and meta and you should be ok (no need to encode anything):
<?php
header ('Content-type: text/html; charset=utf-8');
?>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
</body>
</html>
回答4:
The following mbstring-variables should be set via php.ini or vhost-configuration (httpd.conf; doesn't work per directory [via .htaccess]):
mbstring.language = Neutral
mbstring.internal_encoding = UTF-8
mbstring.func_overload = 7
The just leave the code as it was, make sure your Editor/IDE only saves files as UTF-8 and deliver everything as UTF-8 (via HTTP-header or META-tag).
See also: PHP Manual – Multibyte String – Function Overloading Feature
来源：https://stackoverflow.com/questions/8573612/unicode-in-php