Lecture 7: Statics

Question 1

Static variables

Answer 1

Lifetime: point of initalization til the end of the program

Declared and initialized only once

Question 2

If static var is not initialized explicitly, it is initialized to

Answer 2

0 (of that data type)

Question 3

Difference between const and static variables

Answer 3

Constant variables –> retain same value throughout the scope
Lifetime: initialization til end of scope
Access: initialization til end of scope
Static variables –> retain same memory location throughout the entire program
Lifetime: initialization til end of program
Access: only in the scope

Question 4

Static data member/
static class member

Answer 4

Part of class, but not part of any individual object
	Shared by all instances of the class, instead of belonging to a single one
	Declared inside class
	Initialized outside class
	Created even no object of the class is created
	Remains in memory even after all objects of the respective class are deleted
Used to store information that is required by all objects

Question 5

Can a private static member be accessed outside the class?

Answer 5

Yes, but only when it is being initialized

Question 6

Methods of accessing a static data member or function

Answer 6

1. Like a normal data member or function(through any created object)
2. Using scope resolution operator

Question 7

Static member function

Answer 7

a member function of a class that does not require being called by any individual object
can only access static data members

Question 8

Why can a static member function only access static data members?

Answer 8

This pointer is not implicitly passed to static member functions –> cannot access the data members of whatever object we are trying to call them through
If pointer of the object is passed explicitly, then function can access data members

Question 9

Can regular member functions access static data members?

Answer 9

Yes

Question 10

Alternative to using static data members

Answer 10

Global variables.

Accessible to all, so go against data encapsulation