Check some array values within another array

Question

I need to test if an array has some values that are mandatory by comparing within another array, I currently count the required values, open a loop, and check if the checked values were in the same amount:

    private function validate_required($data, $required) {
        $c = count($required);
        $a = 0;
        foreach ($data as $key) {
            if (in_array($key, $required)) {
                $a += 1;
            }
        }
        if ($a != $c) {
            throw new \Exception('O elemento {elemento} não possui todos os atributos obrigatórios', 'ex0893');
        }
        return true;
    }

What would be a more natural way to do this test ?

OBS:

Not all values of the first array are required in the second.

The array is one-dimensional.

Answer 1

I suggest using the function array_intersect which gives you the interjection of two arrays. For the case in question if the intersection results in the input array then all elements of $required exist in $data:

private function validate_required($data, $required) {
    $inBoth = array_intersect($data, $required);
    if (count($inBoth) !== $c) {
        throw new \Exception('O elemento {elemento} não possui todos os atributos obrigatórios');
    }
    return true;
}

See this example working on Ideone

Wouldn’t it be better to return false also when it’s not valid ? It’s strange a method that returns boolean only to be able to return true and never false. The code would be much simpler:

private function validate_required($data, $required) {
    $inBoth = array_intersect($data, $required);
    return count($inBoth) === $c;
}

In addition it would also avoid having to call the method within a try catch because I would no longer make an exception.

Has also array_intersect_key if you want to calculate the interjection based only on the key, assuming that each element of the array has key and value.