Extended Classes

[mahdoum2]

I have a main class and other sub classes that are extensions of the main class. I want to have a variable in the main class that can be affected by the sub classes... I'll try to explain better.

$main = new MAIN; // main class
$sub = new SUB;// sub class 1 extension of main
$sub2 = new SUB2; //sub class 2 extension of main

$sub->testvar++;
echo $sub->testvar; //test var is located in the main class
// will output 1

$sub2->testvar++;
echo $sub2>testvar;
//wil output 1

What I want the program to do is realise that testvar has been changed by sub and i want sub2 to output 2 and not 1.

I'm not sure how to implement this into classes, I realise that sub and sub2 both have same structure of main but completly different memory addresses.

So how can I fix this?

[Barand]

[code]
class my_main {
    static  $testvar;
    
}
class my_sub extends my_main {
    function  test() {
        echo ++my_main::$testvar, '<br>';
    }
}

$a = new my_sub;
$b = new my_sub;

$a->test();
$b->test();[/code]

[mahdoum2]

Ok thanksI tried that earlier but it didn't seem to work... does putting protected or private before the static affect it?

whats the difference between using classname::object
and $this-> object? Thats where I went wrong

[Barand]

Private will throw an error but protected will work.

In subclass you need to refer to the main class's class variable so refer to it with

mainclassname::$testvar

or

parent::$testvar;

$this->$var refers to the var in the current instance.