Pass variable number of variables to a class in PHP

Question

I need to pass a variable number of strings to instantiate different classes. I can always do a switch on the size of the array:

switch(count($a)) {
case 1:
    new Class(${$a[0]});
    break;
case 2:
    new Class(${$a[0]}, ${$a[1]});
    break;
etc...

There has to be a better way to do this. If I have an array of strings ("variable1", "variable2", 'variable3", ...), how can I instantiate a Class without manually accounting for every possibility?

Answer 1

<?php

new Example($array);

class Example
{
    public function __construct()
    {
        foreach (func_get_args() as $arg)
        {
            // do stuff
        }
    }
}

Answer 2

Look here. Does method 2 help ? Also, perhaps by moving the switch to the constructor (if that is practical) you would be able to hide this from the rest of the code.

Answer 3

You can use an array to pass variable number of variable to the class, for example:

<?php

class test
{
  private $myarray = array();

  function save($index, $value)
  {
      $this->myarray[$index] = $value;
  }

  function get($index)
  {
     echo $this->myarray[$index] . '<br />';
  }
}

$test = new test;
$test->save('1', 'some value here 1');
$test->save('2', 'some value here 2');
$test->save('3', 'some value here 3');

$test->get(1);
$test->get(2);
$test->get(3);

 ?>

Output

some value here 1
some value here 2
some value here 3

You could also use the __get and __set magic methods to save info easily.

Answer 4

// Constructs an instance of a class with a variable number of parameters.

function make() { // Params: classname, list of constructor params
 $args = func_get_args();
 $classname = array_shift($args);
 $reflection = new ReflectionClass($classname);
 return $reflection->newInstanceArgs($args);
}

How to use:

$MyClass = make('MyClass', $string1, $string2, $string3);

Edit: if you want to use this function with your $a = array("variable1", "variable2", 'variable3", ...)

call_user_func_array('make', array_merge(array('MyClass'), $a));

Answer 5

It seems that reflection can pull this one out of the hat for you. This comes to you courtesy of the PHP call_user_func_array notes. The following code will create a class by calling the constructor with the contents of your array.

<?php
// arguments you wish to pass to constructor of new object
$args = array('a', 'b');

// class name of new object
$className = 'ClassName';

// make a reflection object
$reflectionObj = new ReflectionClass($className);

// use Reflection to create a new instance, using the $args
$command = $reflectionObj->newInstanceArgs($args);
// this is the same as: new myCommand('a', 'b');

?>

Answer 6

If you must do it this way, you can try:

$variable1 = 1;
$variable2 = 2;
$variable3 = 3;
$variable4 = 4;

$varNames = array('variable1', 'variable2', 'variable3', 'variable4');
$reflection = new ReflectionClass('A');
$myObject = $reflection->newInstanceArgs(compact($varNames)); 

class A
{
    function A()
    {
        print_r(func_get_args());
    }
}

Answer 7

have a look at the factory design pattern:

class Factory {
  public static function CreateInstance($args) {
    switch(func_get_num_args()) {
      case …:
        return new ClassA(…); break;
      case …:
        return new ClassB(…); break;
    }
  }
}