1. Classes & Objects
CSCE 121
J. Michael Moore

2. Datatypes
Simple
Compound
int, double, bool, etc.
Homogeneous
Heterogeneous
Array
Vector
struct
Class

3. Procedural Programming
So far the focus is on the steps, actions, and functions.
Data is subordinate to functions.
Object Oriented Programming
Focus is on the data.
Functions are subordinate to the data.

4. Object Oriented Model real world objects (mostly) Grouping
Related data (Attributes)
In C++ called data members
Related actions (Methods)
In C++ called member functions
Communication occurs through messages
Object is spoken to by calling a method on it.

5. Concept of Class Class is a generic description
Think blueprint
Object is an instance of the class
Think the blue house on the corner
And the red one on the next block
And the green one next door
I.e. there are multiple instances of a single class

6. Information Hiding / Encapsulation
Visibility
Creating for others to use (e.g. make a Library)
Information Hiding / Encapsulation
Public
Want some things visible to others
What
Tend to be methods / member functions
Private
Want some things hidden from others.
How
Might Change
Tend to be data members / attributes

7. Interface Public Attributes Methods Private Methods Attributes
Call with parameters
Private Helper Functions
Rare
Get / Set values and enforce rules.
Accessor & Mutator methods (getters/setters)
Constructor (initializes object)

8. C++ Note Struct and class are almost interchangeable in C++
Struct was used in C for heterogeneous data
Class adopted into C++ (label was common in other languages)
Class concept groups not only heterogeneous data, but the methods that act on them.
This capability was given to structs as well.
Differ in default visibility
Class is private by default
Struct is public by default