1. Static Members
Sharing is caring…

2. Single Copy
Some things only need/want one of:
Constants
NextID

3. Static
Static : Shared
Member for which very object of class shares value
Student
mascot: Storm
student1
name: Bob mascot:
student2
name: Jane mascot:

4. Static Changing static variable in one changes for all: Student
mascot: Storm
student1
name: Bob mascot:
student2
name: Jane mascot:

5. Static Changing static variable in one changes for all:
student1.setMascot("Bruin")
Student
mascot: Bruin
student1
name: Bob mascot:
student2
name: Jane mascot:

6. Special Static Rules
Non-const & non-literal member variables not initialized in constructor or declaration:
.h file:
Get own initialization outside of class
.cpp file:

7. Static Functions Static Functions May only access static variables
Every object guaranteed to give the same answer
Student
mascot: Bruin
student1
name: Bob mascot:
student2
name: Jane mascot:

8. Static Functions Static Functions
Every object guaranteed to give the same answer
Allowed to call static functions directly on class: CLASSNAME::function()

9. Book Example : Counter Circle with static int : number of Circles
.cpp:

10. Book Example : Counter
Constructors add to counter

11. Constant
Constants are good things to share:
In .cpp

12. Constant Inside class, access via variable name:
From outside the class, need fully qualified name:

13. Static Rules of Thumb OK to make static Think long and hard first…
Constants
Think long and hard first…
Something you think should only be one of
Functions you want to access through class
Factory Functions
Function Libraries (java style)