Object-Oriented Programming

A bit of ad : OOP ask a effort in the beginnings ...

Java supports the Object-Oriented Programming (OOP) approach.

OOP focuses on the design of data-types (called objects or classes) rather than algorithms

Why is this distinction important?

Objects are nouns, Algorithms are verbs

If you want to put a windows in a wall, you don't say :

"Let's use a hammer to make a hole in that wall, then let's measure the size of the hole, then lets buy some piece of wood that we will put together, then ...

You say : Let's decide to have a windows in that wall

You know first what you want and then you think of the way you will get it

Which is an easier task?

• identify the actions that apply to a given noun

• identify those objects to which a given action might be applied

• Example : Verb "to buy" / Object "Car"

isn't it easier to list the actions that you can do with a car (to buy, to sell, ...to drive°) than to list all the object you can buy ... and forget lots of them ?

What is easier?

• identifying similar object classes

is a relationship

• specifying general-purpose algorithms

with lots of "if then else" statements

Advantages of OOP

• promotes design abstraction (hiding details)

• promotes code reuse

• consolidates specification and interface ... encapsulation

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