City Office

<?php

class Driver
{
    private int $serial_number;

    public function setSerialNumber(int $number): void
    {
        $this->serial_number = $number;
    }

    public function getSerialNumber(): int
    {
        return $this->serial_number; 
    }
}

$driver = new Driver();
$driver->setSerialNumber("Version 1b"); // This will throw a TypeError

<?php

class IdentityCard
{
    private int|null $id = null;

    public function assign(int|float $id): void
    {
        $this->id = intval($id);
    }
}

$card = new IdentityCard();
$card->assign(5.0);

Instructions

You have been working in the city office for a while, and you have developed a set of tools that speed up your day-to-day work, for example with filling out forms.

Now, a new colleague is joining you, and you realized your tools might not be self-explanatory. There are a lot of weird conventions in your office, like always filling out forms with uppercase letters and avoiding leaving fields empty.

As a first step you decide to add PHP type declarations so that it is easier for your new colleague to hop right in and start using your tools.

1. Declare the types for the Address class

Add property type declarations to each of the Address class properties declared. Each class property should be declared as a string.

2. Declare the types to fill out the form with blank values

Add a parameter type declaration and a return type declaration to the blanks method in the Form class. The method should take in an integer length, and return a string representation of the blank line.

3. Declare the type when splitting a value into separate letters

Add a parameter type declaration and a return type declaration to the letters method in the Form class. The method should take in a string, representing words, and return an array of letters.

4. Declare the type when checking if a value will fit into a form

Add parameter type declarations and a return type declaration to the checkLength method in the Form class. The method should take in a string word, and an integer maximum length, and return a true or false value.

5. Declare the type when formatting an address in the form

Add a parameter type declaration, making use of the Address class updated previously, and a return type declaration to the formatAddress method in the Form class. The method should take in an Address and return a formatted string.