in a situation like that below,
class my_class { public __construct($params = array()){ **** do something } } $other_object = new some_class(); $object = new my_class(array( 'var1' => 'test' 'object' => $other_object)); $other_object will be passed by reference or by value?
Objects are always references, except you clone it explicitly.
You can use spl_object_hash() to retrieve the "object id" and then compare them against each other. Remember, that once an object is removed from the memory by the garbage collector, the ID may get reused.
$tmp = $array[0]; $tmp['item'] = "something"; var_dump($array); \\ original values
$tmp and expect $array to change? Of course this doesn't work.var tmp = arr[0]; tmp['item'] = "something"; console.log(arr); Arr[0] has been changed since the it is passed by reference. I call it strange behaviour if you say objects are passed as references but this object in an array is acting like a value.$array[0]?
Objects in PHP 5 are always passed by reference. With the help of debug_zval_dump() you can check refcount for variable to calculate number of references to the object instance. Pay attention to the note in documentation, you will found many interesting things about passing a variable to a function.
as of PHP 5 PHP object variable contain the reference or identifier to the actual variable. here is an example to demonstrate this.
class test{ public $test = 1; } $obj1 = new test; $orginal = [$obj1,array(2),3]; $copy = $orginal; echo 'orginal array'; var_dump($orginal); echo 'copy of orginal'; var_dump($copy); //after changing $copy[0]->test = 'changed'; $copy[1][0] = 'changed'; $copy[3] = 'changed'; echo 'orginal array after changing its copy'; var_dump($original); echo 'copy of orginal after changing'; var_dump($copy); the output for this is
original array array (size=3) 0 => object(test)[38] public 'test' => int 1 1 => array (size=1) 0 => int 2 2 => int 3 copy of original array (size=3) 0 => object(test)[38] public 'test' => int 1 1 => array (size=1) 0 => int 2 2 => int 3 original array after changing its copy array (size=3) 0 => object(test)[38] public 'test' => string 'changed' (length=7) 1 => array (size=1) 0 => int 2 2 => int 3 copy of original after changing array (size=3) 0 => object(test)[38] public 'test' => string 'changed' (length=7) 1 => array (size=1) 0 => string 'changed' (length=7) 2 => string 'changed' (length=7) when the object in the copy is changed then the original object is also changed but the array and variable remain unchanged since they are passed as value.
more info about object reference refer : Objects and reference
