1. Lesson Objectives Aims Key Words
You should be able to identify the features of object oriented languages
You should be able to distinguish between object oriented and procedural languages
Identify benefits of object orientation
Key Words

2. Object Oriented Programming
The two most common methods of programming are procedural and object oriented – but what does this mean?
Mmm object orientation

3. Procedural Languages
Procedural programming is all about giving the computer instructions… step by step – in sequence
Procedural programming relies on procedures (aka routines/subs) containing instructions to be carried out by the computer

4. Object Oriented Programming (OOP)
Object Oriented Programming is where things get a bit cleverer and flexible
Instructions are carried out using objects
An object is part of the programme that is able to carry out actions and interact with other elements of the programme
OOPs I did it again

5. Object Oriented Programming (OOP)
Objects have properties and methods… these are easily compared to real life objects
We also rely on classes; these are the blueprints for our objects and outline some key features and capabilities of the object.
Object: A person
Property: Harold (name)
Method: Pose for stock photos (something the object is capable of doing)

6. Classes
So the class is a blueprint for our objects. They contain reusable elements that are common amongst a set of objects.
Classes can contain properties and/or methods.
Here’s a class diagram…
Person
Name
Weight
Eye Colour
Talk
Walk
Class name
Properties
Methods

7. Classes
Encapsulation is when properties for an object aren’t seen – they may be used by the object for calculations but we don’t see them
Inheritance is when certain properties are inherited from one class to another to prevent repetition of properties or methods
Superclass
Person
Name
Weight
Eye Colour
getWeight()
getEyeColour()
Male
Beard Length
Beard Colour
getBeardLength()
Female
getPresident()
Is President?
Subclasses

8. Object
Ivor: Male
Weight: 14st
Eye Colour: Green
Beard Length: 40cm
Beard Colour: Grey
Weight and Eye Colour have been inherited from the super class!
Male
Beard Length
Beard Colour
getBeardLength()
Because of encapsulation the properties may be hidden (private)… we’ll need to use a method to check them.
Hillary: Female
Weight: 14st
Eye Colour: Green
Beard Length: 40cm
Beard Colour: Grey
getPresident()
“Yes”

9. Which is better?
Procedural programming provides little protection for data – it’s easy for variables to be overwritten by accident causing the programme to behave in a way that wasn’t intended
It’s difficult to reuse parts of procedural code
OOP takes advantage of elements having certain things in common with each other

10. Which is better?
Procedural Programming is based on procedures operating based on data.
OOP combines the two – procedures and data to form the objects

11. Review/Success Criteria
You should know
You should be able to identify the features of object oriented languages
You should be able to distinguish between object oriented and procedural languages
Identify benefits of object orientation
You you you oughta know