namespace my;
const DHA=__NAMESPACE__."you are accessing constant"; //generate parse error
const DHA=__NAMESPACE__,"you are accessing constant"; //generate parse error
I tried concating using '.' and ',' but both it gives
Parse error: syntax error, unexpected '.', expecting ',' or ';'
EDIT (UPDATE) : This is a bug in PHP 5.5. It has been resolved in 5.6. https://wiki.php.net/rfc/const_scalar_exprs.