Object-oriented programming is a coding design that uses data to represent a set of instructions. It is a programming paradigm with an object concept and an abstract policy for program development. It consists of attributes that describe the state and methods used to implement object behavior, completing the integration and unification from the data model to the processing model.
What is object-oriented programming?
Object-oriented programming (OOP) is a coding design that uses data to represent a set of instructions. OOP design revolves around specialized classes that can be instantiated as objects.
Unlike procedural or functional programming, OOP gives us scope to express our code more fully. While previous paradigms often had no structures, OOP encourages the use of specialized structures called classes.
Methods are functions that perform specific tasks in a class. Properties are like variables that describe characteristics or characteristics of a class. Methods can operate independently or are often based on class properties. Ultimately, the two work together to realize the concept of OOP.
Advantages of Object-Oriented Programming
So how does object-oriented programming help you write better programs?
OOP reduces the complexity of the code base.
It can help us express our code clearly and make it more readable.
Programs written in OOP are generally more scalable.
It simplifies code testing and debugging.
OOP eliminates code duplication and establishes the DRY (don’t repeat yourself) principle.
OOP code is generally more modular, encouraging separation of concerns.
Class composition and inheritance make code easier to reuse.
Abstraction improves the security of the code base.
Disadvantages of Object-Oriented Programming
Although the advantages of OOP outweigh the disadvantages, the disadvantages cannot be ignored:
It may be slower than functional programming.
OOP has a steep learning curve.
Script folders and files grow as the application expands.
Object-Oriented Programming Structure
OOP revolves around a strict architecture. Here are some terms we will learn about:
Classes
A class is a collection of code that is a representation of data that performs similar operations. We can think of classes as object handlers because we can use object handlers to instantiate objects.
Methods
Methods define how a class accomplishes its task. A class can contain one or more methods. We can think of methods as the way a class shares responsibilities within itself.
For example, a unit converter class might contain methods to convert Celsius to Fahrenheit. It might include another way to change grams to kilograms.
Attributes
Attributes are elements or attributes that describe a class. For example, a unit converter class might contain properties such as converting units. We can define methods that act on these properties.
Like methods, we can access (certain) properties from class instances.
Object
Simply put, an object is an instance of a class. When you instantiate a class, the resulting object uses that class as a blueprint for its properties and methods.
Principles of Object-Oriented Programming
Object-oriented programming brings some principles to the programming table. Each of these puts it ahead of traditional programming.
Abstraction
The abstract concept of OOP is that you don’t need to know how something works. It allows us to wrap code in a simple language without worrying about the complexity behind the scenes of the program.
For example, we don’t need to worry about the logic, filtering algorithms or functions behind the submission operation. As users, all we see and care about is the send button.
Object-oriented programming helps us abstract logic by presenting a single task as a single call. For example, while a unit converter class may do a lot of calculations in the background, we can run its kilogram to gram converter by calling a single method:
class_instance.convert_gram()
Where class_instance is the object, convert_gram is the method of the converter class.
Encapsulation
Encapsulation is one of the ways to create abstraction in object-oriented programming. Each object is a collection of data treated as an entity. The data in the object includes properties and methods hidden in the global space.
Generally, encapsulation allows us to wrap class data privately in an object. Therefore, the contents of one object do not interfere with the other. Only the object's inherent methods and properties can change it.
For example, methods in a unit converter object should not change properties of another object without inheritance or composition.
Encapsulation allows us to change the content or structure of an object without worrying about the public interface.
Inheritance
Inheritance allows us to reuse the contents of a class (called a superclass) in another class called a subclass. When a class inherits from a superclass, it automatically gets its properties and methods.
In addition to the properties inherited from the superclass, subclasses can also have their own properties and methods.
For example, inheritance will come in handy if we want a class to use data from an external module. It also ensures that we don't repeat ourselves when writing code.
Therefore, creating subclasses can also save a lot of time. Instead of creating new classes for everything, we can create a base class and extend it into new subclasses, borrowing existing functionality.
Inheritance is useful, but knowing when to use composition is a basic programming principle.
Polymorphism
Polymorphism is the result of inheritance. It allows you to maintain method or property names in different objects where you can use them as needed.
This concept ensures that a class method can be used dynamically in different classes and inherit it from the base class.
For example, a generic game object can define movement methods. Subclasses can define exactly how their specific movement occurs. The controlling code then doesn't need to know how the individual classes are moved, only that they can all be moved via the common method.
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