Get array values by keys

Question

I am searching for a built in php function that takes array of keys as input and returns me corresponding values.

for e.g. I have a following array

Answer 1

foreach($input_arr as $key) {
    $output_arr[] = $mapping[$key];
}

This will result in $output_arr having the values corresponding to a list of keys in $input_arr, based on the key->value mapping in $mapping. If you want, you could wrap it in a function:

function get_values_for_keys($mapping, $keys) {
    foreach($keys as $key) {
        $output_arr[] = $mapping[$key];
    }
    return $output_arr;
}

Then you would just call it like so:

$a = array('a' => 1, 'b' => 2, 'c' => 3);
$values = get_values_for_keys($a, array('a', 'c'));
// $values is now array(1, 3)