OOP – Object-Oriented Programming on kodkod | Intro Course

Classes and Objects: From the Problem to a Complete Class

Mon, 01 Jan 0001 00:00:00 +0000

In this lesson

This lesson is built as one story, in the same order as the slides. We start from a small bank system written with dictionaries and functions, see where it breaks, and in every chapter add one tool that solves one problem:

Objects at Work: State, Information Hiding, Properties and a Complete Class

Mon, 01 Jan 0001 00:00:00 +0000

In this lesson

This lesson is built as one story, in the same order as the slides. Every chapter relies on the previous one:

Inheritance and super: Similar Classes Without Duplicated Code

Mon, 01 Jan 0001 00:00:00 +0000

In this lesson

This lesson is built as one story, in the same order as the slides:

Chapter 1 — why inheritance: the same code twice, and how to inherit instead of copying
Chapter 2 — overriding and super(): inheritance, but not exactly — changing only part of the behavior

At the end of the lesson — practice, and a mini project that connects both chapters.

Polymorphism: a Common Interface, Different Behavior

Mon, 01 Jan 0001 00:00:00 +0000

What will we learn?

What Polymorphism is.
A Common Interface: the same method, different behavior for each type.
Why it replaces the if type == ....
Duck Typing: Python’s flexible version.

Why do we need this?

Suppose a payment system needs to charge a customer, and the customer can pay by credit card, by PayPal or by bank transfer. Without Polymorphism:

Single Responsibility in OOP and Composition Versus Inheritance

Mon, 01 Jan 0001 00:00:00 +0000

What will we learn?

The Single Responsibility Principle (SRP) at the level of a Class.
Composition: an object made of other objects.
Composition versus Inheritance: how to choose.

Why do we need this?

In the clean code topic we learned SRP for functions: every function does one thing. Exactly the same principle applies to Classes, and there it is even more important, because a big Class is a “pile” of data and behavior. When every change (in the receipt format, in the payment method, in the VAT calculation) touches the same Class, it becomes fragile and scary to change.

Guided Practice: From a Verbal Requirement to a Class Structure

Mon, 01 Jan 0001 00:00:00 +0000

What will we learn?

This is a workshop lesson. We will take one verbal requirement, and go together through the whole process: