Unit_8: Encapsulation

Question 1

Explain public, private protected.

Answer 1

• public: visible to any user of a class X object
• private: visible only to X’s own member functions => better security and reliability, and better control of data locally
• protected: visible in X’s member functions and member
  functions of subclasses (derived classes) of X

Question 2

compare Private vs Protected

Answer 2

we try to isolate functionality in asuperclass – i.e., if the superclass owns a variable they should be defining ways to manipulate it

• This is a general principle you should always follow!
  Subclasses should deal only with the things they
  are responsible for

Question 3

What is Unique C++ features? Why need it?

Answer 3

friend

allows a function, class, or method to access private and protected members of another class

Question 4

Why protected (in Java) insecure?

Answer 4

protected members are accessible by subclasses AND classes in the same package
=> should be private, with
protected accessors/mutators that can be inherited by children