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11.1: Object-Oriented Programming Basics

Last updated

Mar 30, 2025
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- 11.0: Introduction
- 11.2: Classes and Instances

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Learning Objectives

By the end of this section you should be able to

Describe the paradigm of object-oriented programming (OOP).
Describe the concepts of encapsulation and abstraction as they relate to OOP, and identify the value of each concept.

Grouping into objects

Object-oriented programming (OOP) is a style of programming that groups related fields, or data members, and procedures into objects. Real-world entities are modeled as individual objects that interact with each other. Ex: A social media account can follow other accounts, and accounts can send messages to each other. An account can be modeled as an object in a program.

Checkpoint: Using objects to model social media

Access multimedia content

Concepts in Practice: OOP

Consider the example above. Which is a field in Ellis's 12/18/23 post?

Ellis's followers list

Ellis's username

What does an object typically model in object-oriented programming?

program code
real-world entity

Encapsulation

Encapsulation is a key concept in OOP that involves wrapping data and procedures that operate on that data into a single unit. Access to the unit's data is restricted to prevent other units from directly modifying the data. Ex: A ticket website manages all transactions for a concert, keeping track of tickets sold and tickets still available to avoid accidental overbooking.

Checkpoint: Encapsulating concert ticket information

Access multimedia content

Concepts in Practice: Encapsulation

Consider the example above. Suppose the venue has to be changed due to inclement weather. How should a programmer change the website object to allow changes to the Venue field?

Add a procedure to change the field.

Allow users direct access to the field.

No valid way to allow changes to the field.

Which is a benefit of encapsulation when developing complex programs?

All objects can easily access and modify each other's data.
Each object's data is restricted for intentional access.

Abstraction

Abstraction is a key concept in OOP in which a unit's inner workings are hidden from users and other units that don't need to know the inner workings. Ex: A driver doesn't usually need to know their car engine's exact, numerical temperature. So the car has a gauge to display whether the engine temperature is within an appropriate range.

Checkpoint: Abstracting data in a countdown calculator

Access multimedia content

Concepts in Practice: Abstraction

Consider the car example in the paragraph above. Suppose the designer decided to remove the engine temperature indicator. Would this be a good use of abstraction?

Which is a benefit of abstraction?

improved view of information
high visibility of information

Learning Objectives

Grouping into objects

Checkpoint: Using objects to model social media

Concepts in Practice: OOP

Encapsulation

Checkpoint: Encapsulating concert ticket information

Concepts in Practice: Encapsulation

Abstraction

Checkpoint: Abstracting data in a countdown calculator

Concepts in Practice: Abstraction

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