PHP mb_convert_encoding problem record

I recently discovered a problem. When using the mb_convert_encoding function to transcode, some special symbols (???) were removed and replaced with question marks.

Then try to replace first and then transcode.

The code is as follows

<code><span>$arr</span> = <span>array</span>(
            chr(<span>0x99</span>) => <span>'&trade;'</span>, <span>//转gbk小心</span>
            chr(<span>0xA9</span>) => <span>'&copy;'</span>,
            chr(<span>0xAE</span>) => <span>'&reg;'</span>,
        );
mb_convert_encoding(strtr(<span>$str</span>,<span>$arr</span>),<span>'gbk'</span>,<span>'utf-8'</span>);
</code>

But there is still a problem, the main problem still lies in this product.

PS:

• mb_convert_encoding will appear?
• iconv added //ignore will not
• mb_detect_encoding function obtain the string (?) encoding is 'ISO-8859-2'

temporarily recorded

The above introduces the PHP mb_convert_encoding problem record, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.