Global and Local and Private Functions (Javascript)

Question

I am currently reading a book on Javascript by Pragmatic, and I\'m confused about one thing. They have a section on how to make variables global, local, or private.

Answer 1

Private variables only make sense when you are constructing objects. The typical prototype pattern has you add any necessary variables and helper functions as properties of the instance of the object and/or its prototype, but this has the disadvantage of making them visible to anyone with access to the object. To avoid this, there is an alternative pattern where the variables are local variables of the constructor, and all the methods are declared in the constructor scope and only the public ones are assigned as actual properties of the object.