Object oriented programming - OOP

Objects in programming can have properties and methods contained in them. Lets use a traffic light as an example of an object. Color which is active in a traffic light can be a property, switching to a different light is a method.

Values that are stored within an object persists while the program is active.

It maybe needed to access methods and variables within that class. This can be done with a keyword self. Self indicates that method or a property must be used within that class.

Instance of a class is represented by an object. There may be more than one instance of the same class.

Opposite of OOP (Object Oriented Programming) is functional programming.

Why functional programming may be used instead of OOP? Speed and performance of a functional programming language is usually faster. Please think of assembly language as an example of functional programming.

Many of programmers now days think in terms of OOP since it is a newer technology.

If there is a need to access methods within a class from the class itself, then a keyword self needs to be used.

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Study guide

Object-Oriented Programming Fundamentals Study Guide

Key Concepts:

Object: A self-contained entity that bundles data (properties or attributes) and the procedures (methods or behaviors) that operate on that data.

Property (or Attribute): A characteristic or piece of data associated with an object.

Method (or Behavior): A function or procedure that an object can perform or that can be performed on an object.

Class: A blueprint or template for creating objects. It defines the properties and methods that objects of that class will possess. (Note: This source does not explicitly define "class," but it is a fundamental related concept.)

State: The current values of an object's properties at a given point in time. This state persists while the program is running.

self: A keyword used within a class to refer to the instance of the object that is currently being operated on. It allows methods within the class to access the object's own properties and other methods.

Instance: A specific realization of a class; a concrete object created based on the class blueprint.

Object-Oriented Programming (OOP): A programming paradigm centered around the concept of "objects," which can contain data and code.

Functional Programming: A programming paradigm that emphasizes applying and composing functions. It is presented as an alternative to OOP.

Speed and Performance: Potential advantages of functional programming over OOP in certain scenarios.

Modern Programming Trends: The observation that OOP is widely adopted in contemporary programming.

Quiz:

Explain, in your own words, what an object is in the context of programming, providing a simple example not found in the source material.

What is the difference between a property and a method of an object, based on the traffic light example?

According to the text, how long do the values stored within an object typically persist?

What is the purpose of the self keyword in object-oriented programming as described in the source?

What is meant by the term "instance of an object"? Provide a brief explanation.

According to the source, what is presented as the opposite of Object-Oriented Programming?

What is one potential advantage mentioned for using functional programming instead of OOP?

Based on the provided text, is OOP considered an older or newer programming technology?

Can methods within a class access the properties of the same object? If so, how is this typically done according to the source?

What is the relationship between an object's properties and its current state?

Quiz Answer Key:

An object is a self-contained unit in programming that combines data (properties) and actions (methods). For example, a "Car" object might have properties like "color" and "speed," and methods like "accelerate" and "brake."

A property of an object is a piece of information or characteristic (like the active "color" of a traffic light), while a method is an action or behavior that the object can perform or have performed on it (like "switching to a different light").

The values stored within an object persist while the program is active or running.

The keyword self is used within a class to specifically refer to the instance of the object that is currently being used. This allows the object's methods to access and modify its own properties and call its other methods.

An "instance of an object" is a specific, concrete version or creation of an object based on its class definition. If "TrafficLight" is a class, then a specific traffic light at a particular intersection would be an instance of that class.

The source material states that the opposite of Object-Oriented Programming (OOP) is functional programming.

The source mentions that the speed and performance of a functional programming language can be faster than that of an object-oriented language.

According to the text, many programmers now think in terms of OOP since it is described as a newer technology.

Yes, methods within a class can access the properties of the same object. This is typically done using the self keyword to indicate that the property belongs to the current instance.

An object's properties hold the data that defines its current state. The specific values of these properties at any given time represent the object's state.

Essay Format Questions:

Explain the fundamental concepts of object-oriented programming as presented in the provided text, using the traffic light example to illustrate your points. Discuss the relationship between objects, properties, and methods.

Compare and contrast object-oriented programming and functional programming based on the information given in the source. What are the key distinctions, and what is one potential reason for choosing functional programming over OOP?

Discuss the significance of the self keyword in object-oriented programming. Why is it necessary, and how does it facilitate the interaction between an object's methods and properties?

The source mentions that OOP is considered a "newer technology" and is widely adopted. Analyze this statement in the context of programming paradigms. What might be some reasons for the popularity of OOP? (While not directly in the text, consider the benefits implied by its structure).

Using your understanding of the terms "object," "property," and "method," describe how you might model a simple real-world entity (other than a traffic light) as an object in a program. Identify potential properties and methods for your chosen entity.

Glossary of Key Terms:

Object: A distinct entity in programming that encapsulates data (properties) and behavior (methods).

Property: A specific attribute or piece of data associated with an object, describing one of its characteristics.

Method: A function or procedure that is associated with an object and defines an action that the object can perform or that can be performed on it.

self: A special keyword used within the definition of a class's methods to refer to the specific instance of the object being worked with.

Instance: A concrete, individual occurrence of an object created from a class.

Object-Oriented Programming (OOP): A programming paradigm that structures software design around "objects," which can contain both data and code related to the data.

Functional Programming: A programming paradigm that emphasizes the use of pure functions and avoids changing state and mutable data.

State: The set of current values of an object's properties, representing its condition at a particular moment in time.

Frequently Asked Questions about Object-Oriented Programming

Q1: What are the fundamental components of an object in object-oriented programming (OOP)? An object in OOP is a self-contained entity that bundles together two key elements: properties (also known as attributes or data) and methods (also known as behaviors or functions). Properties represent the state or characteristics of the object, holding specific values. Methods define the actions or operations that the object can perform or that can be performed on the object, often manipulating its properties. For example, in the case of a traffic light object, its current color (red, yellow, or green) would be a property, while the action of changing to the next color would be a method.

Q2: How long do the values stored within an object typically last? The values stored as properties within an object generally persist for the duration of the program's execution or as long as that specific object instance exists in memory. This means that an object retains its state, as defined by its properties, until the program terminates or the object is explicitly destroyed or becomes inaccessible (eligible for garbage collection in some languages).

Q3: What is the purpose of the self keyword in the context of object-oriented programming? The self keyword (or its equivalent in other OOP languages, such as this in Java and C++) is a reference variable that allows an object to access its own properties and methods from within its own methods. It essentially points to the instance of the class that is currently being operated on. This is crucial for differentiating between an object's internal variables and any local variables or parameters that might have the same name within a method. By using self, a method can correctly interact with the specific properties and other methods belonging to that particular object instance.

Q4: What is the significance of the term "instance" when discussing objects in OOP? An "instance" of an object refers to a concrete realization or a specific occurrence of a class. A class is like a blueprint or a template that defines the properties and methods that objects of that class will have. When you create an object based on a class, you are creating an instance of that class. Each instance is an independent entity with its own set of property values, although they all share the same methods defined in their class. For example, the concept of a "traffic light" is a class, while a specific traffic light at a particular intersection is an instance of that class.

Q5: What is presented as the primary alternative programming paradigm to object-oriented programming? The source explicitly mentions functional programming as the opposite or alternative to object-oriented programming. These two paradigms represent fundamentally different approaches to structuring and organizing code.

Q6: According to the source, what is a potential advantage of using functional programming over object-oriented programming? The source suggests that a key advantage of functional programming is its potential for faster speed and better performance compared to object-oriented programming. This is often attributed to factors like the absence of mutable state and side effects, which can make functional programs easier to reason about and optimize.

Q7: Why does the source suggest that many programmers nowadays think in terms of OOP? The source attributes the prevalence of object-oriented thinking among modern programmers to the fact that OOP is considered a newer technology compared to other paradigms. This implies that newer educational resources, popular programming languages, and common development practices often emphasize and promote object-oriented principles and methodologies.

Q8: Based on the source, is OOP presented as universally superior to functional programming? No, the source does not present OOP as universally superior. In fact, it highlights a potential advantage of functional programming (speed and performance) and offers a reason for OOP's current popularity (it being a newer technology). This implies that the choice between OOP and functional programming can depend on various factors, such as the specific requirements of the project, performance considerations, and the development team's expertise and preferences.