By reference or not by reference... That's the question

[Firemankurt]

I have not used pass by reference much at all in my designs but I am trying to get more efficient as I learn.

 

Is there any advantage to passing by reference in the model below?

 

<?php
class Core
{
private $_SOMEVALUE; // Number of days till an entry should be removed from database
public function __construct() {
$this->_SOMEVALUE = 1234;
}// End Constuct

public function giveSomeValue() {
return $this->_SOMEVALUE;
}// End addNew()
}// End Class Checklist

class Checklist
{
public $_CORE; // Number of days till an entry should be removed from database
public function __construct(&$CORE_obj) {
$this->_CORE = $CORE_obj;
}// End Constuct

public function test1() {
return $this->_CORE->giveSomeValue();
}// End addNew()
}// End Class Checklist


class Grouplist extends Checklist
{
public function __construct(&$CORE_obj) {
parent::__construct($CORE_obj);
}// End Constuct

public function test2() {
return $this->_CORE->giveSomeValue();
}// End addNew()
}//End Class Grouplist

$CORE_obj = new Core();
$GL = new Grouplist($CORE_obj);
echo '<br />test1='.$GL->test1();
echo '<br />test2='.$GL->test2();
?>

 

The "Core" class in my actual application contains a function "DBquery()" that handles all mysql queries. This keeps me from having to add a global "$mysqli" variable everywhere I use a query and allows for centralized error handling.

[KevinM1]

Not unless Core changes state and you need all of the objects that contain a reference to Core to have those changes reflected within.

[Firemankurt]

Thanks Nightslyr...

 

That is a good point and something I will have to analyze as I continue with my design.

 

Any other thoughts from members?

[ignace]

Objects are always passed by reference, so you don't need the & unless you are passing some other data type like array and you make changes to the passed variable contents. It's best to avoid references in your code, not all programmers understand them and if you are like me you don't work long at one place.

[KevinM1]

Objects are always passed by reference

 

...can't believe I forgot that.

[Firemankurt]

Thanks ignace.

 

So much to remember in such little brain space.  Anyone else need a memory upgrade?