Chapter 3, Programming Languages

Pop quiz – how to fix this?

Q1	A. public, because we want to access it from Main class which is outside the Book class.

Pop quiz – what is the value now?

Q1	A. JavaScript will think this is an error because we try to access .length from an undefined value. This is because JavaScript can't get a property value from an undefined value.

Pop quiz – can you see the difference now?

Q1	A. Circle is a class because it has the definition, and circle is an object, instantiated from the Circle class.

Pop quiz – how to make it global

Q1	A. Just add printAuthor in the Book class prototype, and then all objects created from Book will have the function. If we put the method in every instantiated object, it would be too cumbersome to do it, while having it on prototype guarantees that the method is always created.