Passed and understands, still a question

Code:

class Person {
    public $isAlive = true;
    public $firstname;
    public $lastname;
    public $age;
}
    $teacher = new Person();
    $student = new Person();
        echo $teacher->isAlive;
?>

Question: isAlive is typed with a captial “A”. The following code is written without the second word starting with a captial letter, “firstname”.

Why doesn’t it take “firstName” aswell? is it just because it needs to match description, or is there anything to it.

Now if there isn’t anything to this beyond following description. I would strongly urge that changed due to possible confusion.

Cheers.