objectsAsReference.php

<?php

class A {
	public $var = "blub";
	function __toString() {
		return $var;
	}
}

function makeBlab($object) {
	$object->var = "overridden";	
}
function makeAClass($object) {
	$object = new A();
}
function makeArray($object) {
	$object = [];
}
function makeArrayWithReference(&$object) {
	$object = [];
}

$a = new A();
echo print_r($a, true) . '<br/>';

// objects will be hand over as reference, so will be manipulated in function
makeBlab($a);
echo print_r($a, true) . '<br/>';

// try to override this object with a new initialized one
makeAClass($a);
echo print_r($a, true) . '<br/>';

// try to override this object with an array
makeArray($a);
echo print_r($a, true) . '<br/>';

// try to override this object with an array. Use the values a reference
makeArrayWithReference($a);
echo print_r($a, true) . '<br/>';