php copying array elements by value, not by reference

Question

I have the following code:

$data[\'x\'] = $this->x->getResults();  

$data[\'y\'] = $data[\'x\'];

//some code here to modify $data[\'y\']
//this cause         


        

Answer 1

If you are working with objects, you might want to take a look at clone, to create a copy of an object, instead of a reference.

Here is a very short example :

First, with an array, it works by value :

$data['x'] = array(
    'a' => 'test',
    'b' => 'glop',
);
$data['y'] = $data['x'];
$data['y'][0] = 'Hello, world!';
var_dump($data['x']); // a => test : no problem with arrays

By default, with objects, it works by reference :

$data['x'] = (object)array(
    'a' => 'test',
    'b' => 'glop',
);
$data['y'] = $data['x'];
$data['y']->a = 'Hello, world!';
var_dump($data['x']); // a => Hello, world! : objects are by ref

But, if you clone the object, you work on a copy :
I guess this is your case ?

$data['x'] = (object)array(
    'a' => 'test',
    'b' => 'glop',
);
$data['y'] = clone $data['x'];
$data['y']->a = 'Hello, world!';
var_dump($data['x']); // a => test : no ref, because of cloning

Hope this helps,