Dynamically call Class with variable number of parameters in the constructor

bmarti44 picture bmarti44 · Jan 4, 2012 · Viewed 19.6k times · Source

I know that it is possible to call a function with a variable number of parameters with call_user_func_array() found here -> http://php.net/manual/en/function.call-user-func-array.php . What I want to do is nearly identical, but instead of a function, I want to call a PHP class with a variable number of parameters in it's constructor.

It would work something like the below, but I won't know the number of parameters, so I won't know how to instantiate the class.

<?php
//The class name will be pulled dynamically from another source
$myClass = '\Some\Dynamically\Generated\Class';
//The parameters will also be pulled from another source, for simplicity I
//have used two parameters. There could be 0, 1, 2, N, ... parameters
$myParameters = array ('dynamicparam1', 'dynamicparam2');
//The instantiated class needs to be called with 0, 1, 2, N, ... parameters
//not just two parameters.
$myClassInstance = new $myClass($myParameters[0], $myParameters[1]);

Answer

satrun77 picture satrun77 · Jan 4, 2012

You can do the following using ReflectionClass

$myClass = '\Some\Dynamically\Generated\a';
$myParameters = array ('dynamicparam1', 'dynamicparam2');

$reflection = new \ReflectionClass($myClass); 
$myClassInstance = $reflection->newInstanceArgs($myParameters); 

PHP manual: http://www.php.net/manual/en/reflectionclass.newinstanceargs.php

Edit:

In php 5.6 you can achieve this with Argument unpacking.

$myClass = '\Some\Dynamically\Generated\a';
$myParameters = ['dynamicparam1', 'dynamicparam2'];

$myClassInstance = new $myClass(...$myParameters);