PHP：与关联数组数组中的特定键关联的返回值

Question

In PHP 5.5+, how do I check if the given array of associative arrays contains specific key/value pairs. For example:

$some_array = array(
            array(
                "value"=> 1,
                "k1"=> "austin",
                "k2"=> "texas",
                "k3"=> "us"
            ),
            array(
                "value"=> 15,
                "k1"=> "bali",
                "k2"=> "ubud",
                "k3"=> "indonesia"
            ),
            array(
                "value"=> 26,
                "k1"=> "hyd",
                "k2"=> "telangana",
                "k3"=> "india"
            )
));

How do I return the value associated with k1='bali', k2='ubud' and k3='indonesia'? I can loop through each element to check if that combination exists in the array but is there a simpler way to handle this?

Answer 1

If you have an target array of keys and values, you can filter the main array to only include child arrays that match all the key/value combinations in your target array using array_diff_assoc.

$target =array(
    "k1"=> "bali",
    "k2"=> "ubud",
    "k3"=> "indonesia"
);

$matches = array_filter($some_array, function($item) use ($target) {
    return !array_diff_assoc($target, $item);
});

Inside the array_filter callback, array_diff_assoc will return all the key/value pairs in $target that are not present in $item, so if they all match, you'll get an empty array. Negating that result with ! will return true for matching arrays and false for non-matching arrays.

$matches will be an array of all the child arrays matching your set of key/value pairs, or an empty array if none match.