preg_replace - NULL 结果？
这是一个小示例（下载，重命名为 .php 并在 shell 中执行）：
为什么 preg_replace 返回 NULL 而不是原始字符串？
\x{2192} 与 HTML“→”（“→”）相同。
Here's a small example (download, rename to .php and execute it in your shell):
Why does preg_replace return NULL instead of the original string?
\x{2192} is the same as HTML "→" ("→").
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当我的正则表达式包含
uUTF-8 PCRE 修饰符。如果您的源文本不是 UTF，并且您有此修饰符，您将得到 null 结果。I had an null response when my regular expression included the
uUTF-8 PCRE modifier. If your source text is not UTF and you have this modifier, you'll get a null result.从 preg_replace() 的文档中：
在您的模式中，我认为不支持 u 标志。错误编辑：主题似乎存在某种编码问题。当我删除“147 3.2 V6 - GTA (184 kW)”并手动重新输入时，一切似乎都正常。
编辑 2：在您提供的模式中，有 3 个空格似乎给正则表达式引擎带来了问题。当我将它们转换为十进制时，它们的值为 160（而不是正常的空格 32）。当我用正常的空间替换这些空间时，它似乎起作用了。
我已用下面的下划线替换了有问题的空格：
From the documentation on preg_replace():
In your pattern, I don't think the u flag is supported.WRONGEdit: It seems like some kind of encoding issue with the subject. When I erase '147 3.2 V6 - GTA (184 kW)' and manually re-type it everything seems to work.
Edit 2: In the pattern you provided, there are 3 spaces that seem to be giving issues to the regex engine. When I convert them to decimal their value is 160 (as opposed to normal space 32). When I replace those spaces with normal ones it seems to work.
I've replaced the offending spaces with underscores below:
\x32，然后使用双引号“”）\x2192也不正确。您可以执行以下操作：\x21\x92将两个字节都放入字符串中，但您可能需要查看utf8_encode和utf8_decode警告：preg_replace()：编译失败：test.php 第 7 行中偏移量 0 处的 UTF-8 字符串无效
\x32, then use double quotes "")\x2192is not correct either. You can do:\x21\x92to get both bytes into your string, but you may want to look atutf8_encodeandutf8_decodeWarning: preg_replace(): Compilation failed: invalid UTF-8 string at offset 0 in test.php on line 7
我相信您的正则表达式也存在错误：
~\x{2192}~u尝试替换我的内容，看看是否适合您：
/\x{2192} /uI believe there is also a fault in your Regex expression:
~\x{2192}~uTry replacing what I have and see if that works out for you:
/\x{2192}/u