Static and Const

[jimin-kiim]

• Static variable and function
• Const variable and function

[jimin-kiim]

• normal variable : one per object

Static

Static member variable

• all instance (objects of the class) share the same value
• shared by all the objects that belong to the class
• holds the value which represents the characteristic of the class, not the respective objects
• one per class
• cannot be initialized inside the constructor
  • because the constructor is called when the object is created.
  • should be initialized regardless of the constructor, object creation
  • should be initialized outside of the class
• allocated only once and used for the entirety of the program.

Static member function

• one per class
• cannot access non static class data and functions
  • static member variables and static methods should be used regardless of the objects so it should not depend on non static data or functions

[jimin-kiim]

Const

Const member variable

• a variable that would not be reassigned once assigned

Const member function

• a member function that doesn't modify any data members of the object on which it is called.(read-only function)
  • this restriction is enforced by the compiler
• assures its clients of its benign nature. (safety, readability)
• the keyword 'const' isn't related to the execution, it affects the safety for the programmer