replace the unknown value using php

In my project am using some post, in that post i got a error in browser like this,

"fourth � one - hai" => i paste that error, but i cant get in, Its like a square between fourth and one... But i dont know that issue, 开发者_如何学运维and also i cant string replace that value, and i try to attach the screenshot, that also not working...

And if u want to see that symbol please inspect the space between fourth and one... Help me..

Not sure with your question but check the PHP manual.

http://in.php.net/manual/en/function.mb-split.php