Model Code: Property Checks and Property Setters

Code the property checks

We code the property check functions in the form of class-level (“static”) methods. In JavaScript, this means we define them as method slots of the constructor, as in Book.checkIsbn. Recall that a constructor is a JavaScript object, since in JS, functions are objects, and as an object, it can have slots.

Take care that all constraints of a property as specified in the class model are properly coded in its check function. This concerns, in particular, the mandatory value and uniqueness constraints implied by the standard ...