PHP - how to destroy object and objects it contains?

Question

I have a CLI script written in PHP. In this script I have one instance of mainClass which contains a lot of instances of objects of other types which are stored in PHP arrays. How do I destroy $mainObject and all of the objects it contains?

EXAMPLE CODE:

class mainClass
{
    private $_array1 = array();
    private $_array2 = array();
    private $_array3 = array();

    public function __construct($data)
    {
        foreach ($data['a1'] as $val) {
            $this->_array1[] = new Object1($val);
        }
        foreach ($data['a2'] as $val) {
            $this->_array2[] = new Object2($val);
        }
        foreach ($data['a3'] as $val) {
            $this->_array3[] = new Object3($val);
        }
    }
}

$mainObject = new mainClass($data);

function someFunction(mainClass $mainObject)
{
    unset($mainObject);
}

Does unset($mainObject) will destroy it and all objects it contains?
Do I have to destroy every object separately?
Should I use destructor of the mainClass to destroy objects (call theirs destructors) that $mainObject contains?

score 4 · Answer 1 · edited May 23 '17 at 12:23

4

Best practice is to initialize that object to null.

$mainObject  = NULL;

Reference: What's better at freeing memory with PHP: unset() or $var = null

edited May 23 '17 at 12:23

Community

1
1

answered Apr 09 '15 at 10:03

Sanjay Kumar N S

4,653
4
23
38

score 3 · Answer 2 · edited May 23 '17 at 11:45

You're looking for unset().

But take into account that you can't explicitly destroy an object.

It will stay there, however if you unset the object and your script pushes PHP to the memory limits the objects not needed will be garbage collected. I would go with unset() (as opposed to setting it to null) as it seams to have better performance (not tested but documented on one of the comments from the PHP official manual).

That said do keep in mind that PHP always destroys the objects as soon as the page is served. So this should only be needed on really long loops and/or heavy intensive pages.

kindly refer this link

Best way to destroy PHP object?

I would just add that this will work as long as you don't have circular references. In such case you have to add appropriate destructors to your objects because of a known bug in PHP. — Aleksander Wons, Apr 09 '15 at 10:15

score 2 · Accepted Answer · answered Apr 09 '15 at 09:55

2

unset($mainObject); Will destroy object and memory will be free.

answered Apr 09 '15 at 09:55

Jasmin Patel

36
2

What if a reference to the `$mainObject` exists elsewhere in the code? – Xenos Oct 05 '18 at 14:23

PHP - how to destroy object and objects it contains?

3 Answers3