Question

As seen in this other answer, there are several ways to iterate two same-sized arrays simultaneously; however, all of the methods have a rather significant pitfall. Here are some of the caveats with the methods suggested:

• You can’t use FALSE values in one of the arrays.
• You can only use scalar values in one of the arrays.
• You must use numerically indexed arrays.
• Both arrays must share the same keys.
• Etc.

My question is – is there a method for doing this which doesn’t suffer from any of these (or other) significant caveats?

Bear in mind that I’m simply asking this out of curiosity; I have no use-case in mind, nor do I even know if such a case actually exists or would be useful/practical in a real-world scenario. However, here is some example data:

$arr1 = [ 'a' => 1, 'b' => FALSE, 'c' => new DateTime() ];
$arr2 = [ 'foo', TRUE, 7 ];

Answer 1

You can use a MultipleIterator:

$iterator = new MultipleIterator;
$iterator->attachIterator(new ArrayIterator($array1));
$iterator->attachIterator(new ArrayIterator($array2));

foreach ($iterator as $values) {
    var_dump($values[0], $values[1]);
}

You can find more examples concerning the various options in the docs.