对象无法转换为字符串

Question

The global variable is a class (object) already defined earlier

class Users
{
    private $sql;

    public function __construct() {
        global $sql;
        $this->$sql = $sql;
    }
}

I'm trying to assign the object to a private variable in my other class (Users) so I don't have to use this line global $sql; through all the functions in Users but it's giving me this error:

Catchable fatal error: Object of class Bdcon could not be converted to string in /home/<<NAME>>/public_html/<<NAME>>/classes/class.users.php on line 8

Answer 1

You can't (normally) use an object as property name:

$this->$sql
       ^

But you don't really want:

$this->sql

Whatever, I recommend this other style:

class Users
{
    private $sql;

    public function __construct(Bdcon $sql) {
        $this->sql = $sql;
    }
}