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How to access the method of an object that is inside an object

Hi guys and gals, once again i hit bump in this project.
the thing is that I have 2 classes, well I think it's better if i put the code first:

PHP Code:


		
			
<?php

class foo{

    private $a;

    private $b;

    

    function __construct(){

        $this->a=3;

        $this->b=3;

    }

    

    public function getA(){    return $this->a; }

    public function getB(){    return $this->b; }

    public function setA($t){ $this->a=$t; }

    public function setB($t){ $this->a=$t; }

}



clas bar{

    $private c;

    $private d;

    

    function __construct(){

        $this->c=10;

        $this->d= new foo;

    }

    

    public function getC(){ return $this->c }

    public function getD(){ return $this->d }

    public function setC($t){ $this->c=$t; }

    public function setD($t){ $this->d=$t; }

}

?>

now the problem rises when i want to get the getA() method from an instance of bar, like this:

PHP Code:


		
			
<?php

$house=new Bar;

echo $house->getD()->getA(); // it should output 3 ideally 

?>

but I get this "Fatal error: Can't use method return value in write context"

any ideas on what i am doing wrong? thanks for the help in advance.

That returns 3 for me. Are you trying to do something like the following, because this is really the only way I can think of causing that error you're getting:

php Code:

if (empty($house->getD()->getA()))
{
    
}

yes! i am trying to see if they are empty, I forgot to mention that.

I see, I see! Sadly, empty cannot check the return value, for some unknown reason. I don't know the real reasoning behind it. Assign the value to a variable first, and then check if that variable is empty or not.

php Code:

$iValue = $pHouse->getD()->getA();

if (empty($iValue))
{

}

Awesome, that worked! though I am curious as to why. I'll search more after I finish the project.
Thanks for the help :)

And please let us know, too! Best of luck, my friend :-)