In what scenarios would it be beneficial to use array_keys function in PHP for checking postal code data?

When checking postal code data in PHP, it can be beneficial to use the array_keys function to quickly determine if a specific postal code exists in an array of valid postal codes. This function allows you to retrieve the keys of an array, which in this case would be the postal codes themselves. By using array_keys, you can easily check if a given postal code is present in the array without having to iterate through the entire array.

// Sample array of valid postal codes
$validPostalCodes = array("10001", "20002", "30003", "40004");

// Postal code to check
$postalCode = "20002";

// Check if the postal code exists in the array
if (in_array($postalCode, array_keys($validPostalCodes))) {
    echo "Postal code is valid.";
} else {
    echo "Postal code is invalid.";
}