Passing array of parameters to object constructor

Question

How can I call a object constructor passing an array of parameters so that having:

$array = array($param1, $param2);

I'll be able to call

$abc = new Abc($param1, $param2);

considering that I don't know how many parameters could be set in the array. Is there something like call_object('Abc', array($param1, $param2))?

@JeffPigarelli perhaps if you had worded your question better or given more of an example you would not have got so many "incorrect" answers .... — Manse
– Manse, Commented Dec 16, 2011 at 14:27

augusthur · Accepted Answer · 2015-12-29 01:08:45Z

21

How about using ... (splat operator)?

$array = array($param1, $param2);
$abc = new Abc(...$array); // equal to: new Abc($param1, $param2)

PHP 5.6 is required.

answered Dec 29, 2015 at 1:08

augusthur

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1 Comment

CodiMech25 Over a year ago

Actually this should be marked as the right answer, because PHP 5.6 was released 5 years ago and isn't supported anymore. So users are encouraged to use the latest stable PHP version anyway.

Community · Accepted Answer · 2023-11-17 19:32:19Z

7

The best way is to use an array or object that stores the arguments and you just pass that array/object

Another way would be using Reflection ( https://www.php.net/Reflection ) using newInstanceArgs ( https://www.php.net/manual/de/reflectionclass.newinstanceargs.php )

edited Nov 17, 2023 at 19:32

CommunityBot

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answered Dec 16, 2011 at 14:17

DarkDevine

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Comments

lonesomeday · Accepted Answer · 2011-12-16 14:19:56Z

4

The ideal is to define your constructor to take an array.

If you can't do that, there is a possible workaround. If all parameters to the constructor are optional, you could do something like this with call_user_func_array:

$obj = new Abc;
call_user_func_array(array($obj, '__construct'), $array);

This results in your constructor being run twice: once with no parameters, and once with those in the array. You'll have to decide whether this is suitable for your application.

answered Dec 16, 2011 at 14:19

lonesomeday

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2 Comments

guido Over a year ago

Uhm! What if your Abc constructor need parameters? PHP Fatal error: Uncaught ArgumentCountError: Too few arguments to function Abc::__construct(), 0 passed. So you cannot instanziate the object and then call the constructor. I'm missing something?

lonesomeday Over a year ago

@guido "If all the parameters to the constructor are optional." This is hardly good practice: it's a workaround.

Michael Berkowski · Accepted Answer · 2011-12-16 14:18:15Z

3

Assuming you are able to modify your objects' constructors, a pattern like this isn't uncommon, but requires associative arrays as input:

class Abc {
  public $prop1;
  public $prop2;

  public function __construct($params) {
    if (is_array($params)) {
       $this->prop1 = isset($params['prop1']) ? $params['prop1'] : NULL;
       $this->prop2 = isset($params['prop2']) ? $params['prop2'] : NULL;
    }
  }
}

// Created as:
$params = array('prop1'=>12354, 'prop2'=>54321);
$abc = new Abc($params);

answered Dec 16, 2011 at 14:18

Michael Berkowski

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1 Comment

digitaldonkey Over a year ago

This won't work if you want to use a typed constructor.

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