在PHP中实现类似.Net的集合

Question

So, i would like to implement something like this:

class Collection{
   private $array;
   public function add($object){
      array_push($this->array, $object);
   }
   public function array(){
      return $this->array;
   }
}
class JustaClass{
   public $myCollection;
   public function __construct(){
      $this->myCollection = new Collection();
   }
}

$justAnObject = new JustaClass();
$justAnObject->myCollection->add(new SomeObject());

this works just fine, but i would like to work with it like i do in .Net, ie, when i want to refer to the collection Object, i would like to do it directly, like:

foreach($justAnObject->myCollection as $collectionItem)

and not like

foreach($justAnObject->myCollection->array() as $collectionItem)

Is there any way I can do this? maybe a magic method, or implementing an Iiterator-like interface?

thanks

Answer 1

Let your Collection class implement the Iterator or IteratorAggregate interfaces. There's also an ArrayIterator class, so it's really as easy as just returning an instance of that class:

class Collection implements IteratorAggregate {
  private $array;
  public function add($object){
    array_push($this->array, $object);
  }

  /* required by IteratorAggregate */
  public function getIterator() {
    return new ArrayIterator($this->array);
  }
}

You can then use your class in the following way:

$c = new Collection();
$c->add(1);
$c->add(2);
$c->add('we can even add strings');
foreach($c as $v) {
  doSomething($v);
}