如何检查数组的键值以防止在php中重复输入？

Question

I know this is a very common and repeated subject, but after spending some hours of googling I didn't find the right solution for my problem.

Using a foreach loop I'm filling an array, each row including a key and value. I just want to prevent duplicates or remove them.

$data['products'] = array();
$data['stores'] = array();

foreach ($products as $product) {
    //if (!in_array($product['store_id'], $data['stores'])) {
    if (!array_key_exists($product['store_id'], $data['stores'])) {
        $data['stores'][] = array(
            'store_id'   => $product['store_id'],
            'store_name' => $product['store_name']
        );
    }
}

The result of print_r($data['stores']):

Array
(
    [0] => Array
        (
            [store_id] => 1
            [store_name] => Karaca
        )

    [1] => Array
        (
            [store_id] => 1
            [store_name] => Karaca
        )

    [2] => Array
        (
            [store_id] => 7
            [store_name] => nurteks
        )

    [3] => Array
        (
            [store_id] => 7
            [store_name] => nurteks
        )
)

I tried all suggestions, but I don't know how to figure it out.
Thanks for any kind help!

Answer 1

Use the store ID as the key in the stores array. This will ensure that the entries are unique since array keys are inherently unique.

foreach ($products as $product) {
    $data['stores'][$product['store_id']] = array(
        'store_id'   => $product['store_id'],
        'store_name' => $product['store_name']
    );
}

The two things you tried didn't work because:

1. if (!in_array($product['store_id'], $data['stores'])) {...
   The "needle" ($product['store_id']) is an integer, but the "haystack" ($data['stores']) contains arrays.

2. if (!array_key_exists($product['store_id'], $data['stores'])) {
   You aren't specifying array keys when you use $data['stores'][] to append items, so the store id won't be found as an array key, or if it is, it won't really be the store id, it will just be the automatically assigned sequential index that just coincidentally matches a store id.