returning a reference to another object by creating a another object (confusing)

Question

I am made a class that is called SQL_Connection. The purpose of this class is to return a reference ($con) to the calling variable. Example: $conRef = new SQL_Connection(); Where $conRef would now be a reference of $con and not an instance of SQL_Connection(), if this is possible of course.

The construct function at the end does return $con;, I presume this may be the issue :/

Thanks.

cdhowie · Accepted Answer · 2013-01-18 19:32:55Z

3

Using new implies that you know the exact type of the object you want to construct. The pattern you want to use is a factory method, not a constructor. For example:

class SQL_Connection
{
    public static function create()
    {
        $con = new Other_SQL_Connection();
        return $con;
    }
}

Then invoke SQL_Connection::create() elsewhere to obtain the object reference.

answered Jan 18, 2013 at 19:32

cdhowie

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5 Comments

MichaelMitchell Over a year ago

So essentially I cannot return the variable by just calling the class?

cdhowie Over a year ago

@MichaelMitchell You cannot "call a class." You can call a constructor, but not a class.

Ohgodwhy Over a year ago

could you not just use the __construct() function, create a variable outside of it called $db, and return $this->db = new mysqli();? then instantiating of the class would return the DB?

MichaelMitchell Over a year ago

@Ohgodwhy but from what I was able to understand from this, when you do $var = new Class(), $var cannot be something other than the instance?

cdhowie Over a year ago

@MichaelMitchell The return value of the __construct() function is ignored. In your example, $var will always be an object of type Class, if the constructor does not throw an exception.

Mustafa Shujaie · Accepted Answer · 2013-01-18 19:35:28Z

-1

As I think constructor methods can't return anything

answered Jan 18, 2013 at 19:35

Mustafa Shujaie

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