迭代私有属性中的数组保持

Question

I have the 'Article' class with the private property words which holds and array of Word class objects. I also have getWord method which can return one word:

class Article {
    private $words = Array(1 => new Word(1), 2 => new Word(2), ...);

    public function getWord($wordId) {
        if (array_key_exists($wordId, $this->words)) {
            return $this->words[$wordId];
        } else {
            return NULL;
        }
    }
}

I need to iterate through all exising words. What is the best way to do that?

Currently I'm returning all words as array using another method, but I don't think that is a good option.

Answer 1

If you want to iterate over an Article object, accessing all Word objects, you should implement either the Iterator interface, or IteratorAggregate.

If this is done, iterating would be as easy as this:

foreach ($article as $word) {
    // do stuff with Word object here
}

The easiest way would be to convert your existing getWords method. You could add a new method getIterator as required by the IteratorAggregate interface and implement it like this:

public function getIterator() {
    return new ArrayIterator($this->getWords());
}

If you want to get rid of getWords(), you could also pass the internal array directly.