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phpregexencodingcharacter-encodingspecial-characters

Does preg_replace() change my character set?

I have the following piece of code which seems to be changing my character set.

     $html = "à";
     echo $html;  // result: à
     $html = preg_replace("/\s/", "", $html);
     echo $html;  // result: ?

However, when I use [\t\n\r\f\v] as my pattern instead of the special character \s it works fine:

     $html = "à";
     echo $html;  // result: à
     $html = preg_replace("/[\t\n\r\f\v]/", "", $html);
     echo $html;  // result: à

Why is that?

Solution

  • I have the same problem. It is because of UTF8.

    à is 0xc3a0 in UTF8. In PHP you can write like this: "\xc3\xa0".

    With PCRE the /s match 0xa0 like it was ASCII "Non-breaking space".

    You can use the u flag to resolve the problem.

    $html = preg_replace("/\s/u", "", $html);