replacing multiple utf-8 characters in php

Question

I have a string with multiple utf-8 characters that look like this

\u00b4, \u2019, \u201b, \u2032

I want to replace these with the following html character

'

I'm using the following php code to replace these

$search  = "(\\u00b4|\\u2019|\\u201b|\\u2032)"; 
$replace = "'";

$result = preg_replace($search, $replace, $string);

I keep getting the following warning, and $result is null

Warning:  preg_replace(): Compilation failed: PCRE does not support \\L, \\l, \\N, \\U, or \\u at offset 2 in /...

I have no idea what to do. Any ideas on how to proceed with replacing these utf8 characters is appreciated!

Answer 1

$unicode = "\u00b4 \u2019 \u201b \u2032";
$unicode = preg_replace('/\\\\u[^ ]+/im', "'\r\n", $unicode);
echo $unicode;

You didn't escape the backslashes correctly, you need 2 extra backslashes:

\\\\

Answer 2

对特定的字符代码进行预匹配时，您需要使用\\ x十六进制表示法，而不是unicode表示法-看起来像unicode值。

$search  = "(\xb4|\x2019|\x201b|\x2032)";