在 PHP 中使用 UTF-8 字符集 - 是否需要 mb 函数？
在过去的几天里，我一直致力于将我的 PHP 代码库从 latin1 转换为 UTF-8。我读过两个主要的解决方案，要么用内置的多字节函数替换单字节函数，要么在 php.ini 文件中设置 mbstring.func_overload 值。
但后来我在堆栈溢出上遇到了 this 线程，其中 thomasrutter 的帖子似乎表明只要脚本和字符串文字以 UTF-8 编码，多字节函数实际上对于 UTF-8 来说并不是必需的。
我还没有找到任何其他证据证明这是否属实，如果事实证明我不需要将我的代码转换为 mb_functions 那么这将是一个真正的节省时间！有人能解释一下吗？
These past few days I've been working toward converting my PHP code base from latin1 to UTF-8. I've read the two main solutions are to either replace the single byte functions with the built in multibyte functions, or set the mbstring.func_overload value in the php.ini file.
But then I came across this thread on stack overflow, where the post by thomasrutter seems to indicate that the multibyte functions aren't actually necessary for UTF-8, as long as the script and string literals are encoded in UTF-8.
I haven't found any other evidence whether this is true or not, and if it turns out I don't need to convert my code to the mb_functions then that would be a real time saver! Anyone able to shed some light on this?
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据我了解这个问题，只要你的所有数据都是 100% utf-8 - 这意味着用户输入，数据库，以及 PHP 文件本身的编码（如果其中有特殊字符） - 这是 < Strike>true 搜索和比较操作为true。正如 @ntd 指出的，非多字节 strlen() 在包含多字节字符的字符串上运行时将产生错误的结果。
这是一篇关于编码基础知识的精彩文章。
As far as I understand the issue, as long as all your data is 100% in utf-8 - and that means user input, database, and also the encoding of the PHP files themselves if you have special characters in them - this is
truetrue for search and comparison operations. As @ntd points out, a non-multibyte strlen() will produce wrong results when run on a string that contains multibyte characters.THis is a great article on the basics of encoding.
它们不是“必需的”，除非您使用它们替换的任何 函数（并且您可能正在使用其中至少一个）或明确需要扩展的功能，例如 HTTP 处理。
在努力实现 UTF-8 合规性时，我总是回到 PHP UTF-8 Cheatsheet 添加了一项内容：需要更新 PCRE 模式才能使用
u修饰符。They aren't "necessary" unless you're using any of the functions they replace (and it's likely that you are using at least one of these) or otherwise explicitly need a feature of the extension such as HTTP handling.
When working towards UTF-8 compliance, I always fall back to the PHP UTF-8 Cheatsheet with one addition: PCRE patterns need to be updated to use the
umodifier.一旦您检查或修改多字节字符串，您就需要使用 mb_* 函数。一个非常简单的例子说明了原因：
这会打印出：
As soon as you're examining or modifying a multibyte string, you need to use a mb_* function. A very quick example which demonstrates why:
This prints out:
thomasrutter 表示搜索不需要特殊处理。例如，如果您需要检查 UTF8 字符串的长度，我不知道如何使用普通的
strlen()来做到这一点。thomasrutter indicates that the search does not need special handling. For example, if you need to check the length of an UTF8 string, I don't see how you can do that using plain
strlen().mb_strtoupper 等函数可能也是必要的。 strtoupper 不会将 á 转换为 Á。
Functions such as mb_strtoupper may be necessary, too. strtoupper won't convert á to Á.
有许多函数期望字符串是单字节（有些甚至假设它是 iso-8859-1）。在这些情况下，您需要了解自己在做什么，并可能使用替换函数。有一个相当全面的列表： http://www.phpwact.org/php/ i18n/utf-8
There are a number of functions that expect strings to be single byte (And some even presume that it is iso-8859-1). In these cases, you need to be aware of what you're doing and possibly use replacement functions. There is a fairly comprehensive list at: http://www.phpwact.org/php/i18n/utf-8
您可以使用 mbfunctions 库来扩展 PHP 中的多字节函数：
http://code.google.com /p/mbfunctions/
You could use the mbfunctions library that extends the multibyte functions in PHP:
http://code.google.com/p/mbfunctions/
你可以用这个
http://php.net/manual/en/mbstring.overload.php
设置在 php.ini 文件中，因此您无需更改代码。
但要小心，因为并不是所有的字符串函数都会自动改变。
这是一个：http://php.net/manual/en/function。 substr-replace.php
You can use this
http://php.net/manual/en/mbstring.overload.php
setting in php.ini file, so you don't need to change you code.
But be careful, because not all string function will be automatically changed.
This is one: http://php.net/manual/en/function.substr-replace.php