php 不间断的 utf-8 0xc2a0 空间和 preg_replace 奇怪的行为
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non-breaking utf-8 0xc2a0 space and preg_replace strange behaviour
提问by DamirR
In my string I have utf-8 non-breaking space (0xc2a0) and I want to replace it with something else.
在我的字符串中，我有 utf-8 不间断空格（0xc2a0），我想用其他东西替换它。
When I use
当我使用
$str=preg_replace('~\xc2\xa0~', 'X', $str);
it works OK.
它工作正常。
But when I use
但是当我使用
$str=preg_replace('~\x{C2A0}~siu', 'W', $str);
non-breaking space is not found (and replaced).
未找到（并替换）不间断空间。
Why? What is wrong with second regexp?
为什么？第二个正则表达式有什么问题？
The format \x{C2A0}is correct, also I used uflag.
格式\x{C2A0}正确，我也使用了u标志。
回答by Newbo.O
Actually the documentation about escape sequences in PHP is wrong. When you use \xc2\xa0syntax, it searches for UTF-8 character. But with \x{c2a0}syntax, it tries to convert the Unicode sequence to UTF-8 encoded character.
实际上有关 PHP 转义序列的文档是错误的。当您使用\xc2\xa0语法时，它会搜索 UTF-8 字符。但是在\x{c2a0}语法上，它会尝试将 Unicode 序列转换为 UTF-8 编码的字符。
A non breaking space is U+00A0(Unicode) but encoded as C2A0in UTF-8. So if you try with the pattern ~\x{00a0}~siu, it will work as expected.
不间断空格是U+00A0(Unicode) 但编码为C2A0UTF-8。因此，如果您尝试使用 pattern ~\x{00a0}~siu，它将按预期工作。
回答by hugsbrugs
I've aggegate previous answers so people can just copy / paste following code to choose their favorite method :
我已经汇总了以前的答案，因此人们只需复制/粘贴以下代码即可选择他们最喜欢的方法：
$some_text_with_non_breaking_spaces = "some?text?with 2 non breaking spaces at the beginning";
echo 'Qty non-breaking space : ' . substr_count($some_text_with_non_breaking_spaces, "\xc2\xa0") . '<br>';
echo $some_text_with_non_breaking_spaces . '<br>';
# Method 1 : regular expression
$clean_text = preg_replace('~\x{00a0}~siu', ' ', $some_text_with_non_breaking_spaces);
# Method 2 : convert to bin -> replace -> convert to hex
$clean_text = hex2bin(str_replace('c2a0', '20', bin2hex($some_text_with_non_breaking_spaces)));
# Method 3 : my favorite
$clean_text = str_replace("\xc2\xa0", " ", $some_text_with_non_breaking_spaces);
echo 'Qty non-breaking space : ' . substr_count($clean_text, "\xc2\xa0"). '<br>';
echo $clean_text . '<br>';
回答by DThought
The two codes do different things in my opinion: the first \xc2\xa0will replace TWO characters, \xc2and \xa0with nothing.
在我看来，这两个代码做了不同的事情：第一个\xc2\xa0将替换两个字符，\xc2并且\xa0什么也不替换。
In UTF-8 encoding, this happens to be the codepoint for U+00A0.
在 UTF-8 编码中，这恰好是U+00A0.
Does \x{00A0}work? This should be the representation for \xc2\xa0.
不\x{00A0}工作？这应该是 的表示\xc2\xa0。
回答by Pali
I did not work this variant ~\x{c2a0}~siu.
我没有使用这个变体~\x{c2a0}~siu。
Varian \x{00A0}works. I have not tried the second option and here is the result:
瓦里安\x{00A0}作品。我还没有尝试过第二个选项，结果如下：
I tried to convert it to hex and replace no-break space 0xC2 0xA0 (c2a0)to space 0x20 (20).
我试图将其转换为十六进制并将不间断空格替换0xC2 0xA0 (c2a0)为 space 0x20 (20)。
Code:
代码：
$hex = bin2hex($item);
$_item = str_replace('c2a0', '20', $hex);
$item = hex2bin($_item);
回答by EllisGL
/\x{00A0}/, /\xC2\xA0/ and $clean_hex2bin-str_replace-bin2hex worked and didn't work. If I printed it out to the screen, it's all good, but if I tried to save it to a file, the file would be blank!
/\x{00A0}/、/\xC2\xA0/ 和 $clean_hex2bin-str_replace-bin2hex 有效但无效。如果我将它打印到屏幕上，一切都很好，但是如果我尝试将其保存到文件中，则该文件将是空白的！
I ended up using iconv('UTF-8', 'ISO-8859-1//IGNORE', $str);
我最终使用 iconv('UTF-8', 'ISO-8859-1//IGNORE', $str);
