Functional Programming vs Object-Oriented Programming: Which One is Better?

Functional Programming vs Object-Oriented Programming

If you are a developer or in the software development industry for a very long time, you might have heard an ongoing debate – Functional Programming (FP) vs Object-oriented Programming (OOP).

Many developers have been in the dilemma of using an object-oriented programming style or functional programming. They are still wondering which one is the best fit. As a matter of fact, based on the various features like modularity, control flow, and state handling, the paradigm of programs tends to differ from one another. However, an individual developer or a prominent software development company will prefer a scalable program and easier to maintain and extend.

In fact, it’s not a justified reason to have an in-depth comparison between these two programs as they work on different ideologies and are used for various objectives. They don’t compete against each other when someone talks about them. However, your programming choice depends on what you want to do within your project/application.

Here, in this article, we are going in-depth to understand and know the difference and which one would be the better choice over the other.

What’s a Programming Paradigm?

Programming Paradigm Definition

A programming paradigm is one type of method which is used to solve a certain task in a program. It represents the different principles, strategies, and policies a developer can implement for software development. There are numerous programming languages available for development, each of which must adhere to at least one programming paradigm.

Every programming paradigm has its pros and cons; therefore, every programming language prefers offering multi-paradigm programming instead of sticking to just one. However, having said this earlier, it completely depends on the developer’s preferences and the object of the project.

As a result, it’s hard to find a ‘pure’ language that only supports one programming paradigm. For example, Java is known as an Object-oriented Programming (OOP) language. So now the question comes, is Java 100% OOP? Well, maybe not 100%. However, it secures its position as “one of the purest” OOP languages.

In recent times, you will find many amazing programming paradigms. And these paradigms are categorized into two different categories – imperative and declarative. Logic and procedural programming paradigms, as well as functional and object-oriented programming, are also available.

So, now let’s just focus on Functional programming vs Object-oriented programming in this article.

Functional Programming

Functional programming is a declarative programming paradigm in which code is written as pure functions. It means these functions generate new variables as an outcome instead of modifying them. Since the output of a pure function only depends on the input parameters, each function takes in an input value and offers a consistent output without any alteration. Therefore, it avoids any side effects.

Therefore, functional programming has become popular because of its scalability and efficiency in solving problems. Henceforth, many frameworks and programming languages such as Lisp, Clojure, Wolfram, Erlang, Haskell, F#, R, etc., support functional programming. Moreover, functional programming is a preferred and primary choice for data science work. R is the popular language for it.

Here are some of the important factors we should consider for functional programming.

1. Functional programming language can be converted well into an interactive environment. This helps developers to have an easy understanding of code.

2. It offers many advantages like lazy evaluation, error-free code, nested functions, parallel programming, and efficiency. In a nutshell, functional programming allows developers to write the function with statements to run a specific task for the application.

3. If required, the function can be easily reused and called at any time. Also, it manages the code without doing any changes.

4. The following functions of functional programming are known as first-class citizens.

  • High Order Functions (HOF)
  • Pure Functions
  • Recursion
  • Strict and Non-strict Evaluation
  • Type Systems
  • Referential Transparency

Now, let’s get into the shoes of developers and understand its approach with an example. Here, we will understand how to use these two different programming paradigms. So, let’s consider this given super form that calculates the number1 and number2 field values.

Functional Programming Field Values

Now, here, we will implement functional programming and perform the calculation from the data.

const a = document.querySelector('#number1').value;
const b = document.querySelector('#number2').value;

function sum(a, b)
return a + b;

Then, another function will output the result on the console.

function displayResult(result)

Lets implement the functional programming approach for your custom software project

Object-Oriented Programming (OOP)

Object-Oriented Programming

Object-Oriented Programming manages data and the software structure as per their classes and objects. JavaScript, C++, Java, Python, Ruby, PHP, Perl, Dart, Lisp, Python, Objective-C and Swift are Object-oriented programming languages. Object-oriented programming creates objects that have both data and functions.

In OOP, another application can easily use objects, too. Here, for the same classes, new objects can be created, and code can be easily maintained and modified.
Now, understand the actual meaning of classes and objects.

A set of instructions or blueprints (also known as classes) that construct a data structure for a certain object. They decide what will be in the object (variables) and how it will act.

Thus, blueprints of classes are referred to as objects. However, for object creation, classes work as “templates.” Data – in the form of fields known as attributes, and code – in the form of procedures known as methods, are also included in objects.

Now, let’s consider the above example and implement the approach of object-oriented programing.

Did you know users of Python, which is an object-oriented language, has grown from 50% in 2017 to 58% in 2018 for web development Click To Tweet

Here, we will have to create a class for our form. Now, let’s add following properties in the constructor function:

form: the form element

number1 and number2: input fields

calculateHandler : It’s an event function that binds to the class and displays the sum of inputs on the console.

class SumForm
constructor(form, number1, number2)
this.form = form;
this.number1 = number1;
this.number2 = number2;
this.form.addEventListener('submit', this.calculateHandler.bind(this));

calculateHandler(event) {
console.log(this.number1 + this.number2);
new SumForm(document.getElementById('sum-form'), document.getElementById('number1').value, document.getElementById('number2').value);

OOP is based on the given main features:

Abstraction: It allows the user to use the relevant information. Hence, it enhances the efficiency of the program.

Inheritance: It allows a derived class to inherit the methods, functions, properties, and a base class’s fields.

Polymorphism: Using overloading and overriding, polymorphism helps in doing one task in multiple ways.

Encapsulation: It hides irrelevant data from a user and prevents unauthorized access.

Key Differences: Functional Programming vs Object-Oriented Programming

As per Wikipedia, programs are executed in a particular stateless function evaluation in functional programming. On the other hand, programs are executed as a set of interactive objects in OOP.

Given below table will clear your doubts with its key differences.

Functional ProgrammingObject-Oriented Programming
DefinitionFunctional programming focuses on function evaluation.Object-oriented programming is an objects-based concept.
DataImmutable data is used for Functional programming. Mutable data is used for Object-oriented programming.
ModelFunctional Programming follows the declarative programming model approach.Object-oriented programming follows the imperative programming model approach.
SupportFunctional programming supports parallel programming.Object-oriented programming doesn’t support parallel programming.
ExecutionStatements can be executed in any order in Functional Programming.The execution of statements should be in a particular order.
ElementVariables and Functions are the basic elements of Functional Programming.Objects and Methods are the basic elements of OOP.
UseOnly used when there are few things with more operations.Only used when there are many things with more operations.
IterationRecursion is used for iterative data.Loops are used for iterative data.
Manipulation UnitFunction is the primary manipulation unit in Functional Programming.An object is the primary manipulation unit in OOP.
Side EffectsFunctions don’t affect the code.Methods can have side effects and may impact processors.
Core FocusIt focuses on – How we are doing.It focuses on – What we are doing.
AccessibilityIt does not have any access specifier.It has three access specifiers – Public, Private and Protected.
SecurityIt doesn’t support data hiding. Hence, security is not possible.It provides data hiding. Hence, secured programs are possible.

Functional Programming Pros and Cons

As we know, every coin has two sides. Therefore, you will also find the advantages and drawbacks of functional programming. Now, we are going to discuss functional programming’s pros and cons in detail.

Pros of Functional Programming :

Pros of Functional Programming

Generally, functional programming is used for its front-end development. However, you could still implement this approach for full-stack development if you are skilled and versatile enough. So, what are the functional programming pros? Let’s hear it out.

Powerful Abstraction

Functional programming offers a strong abstraction. By writing a set of pure functions, we may use referential transparency to abstract away and hide complexity. In addition, the distinction between the outcomes of a function call and a basic value can become hazy. It doesn’t matter which one it is as long as you understand what the value is supposed to be. The abstraction of functional programming is its most powerful characteristic. You may zoom in on the problem and solve it one function at a time by relying on how your functions behave.


It’s very easy to read and memorize when we write code using functional programming. It’s easy to guess what goes into your function and what the outcome will be. You’ll have a clear idea of what your function can and cannot perform. You won’t have to deal with states, which makes things easier to comprehend.

Since pure functions never deal with the outside world of concealed states, functional programming is easy to understand. In most functional programming languages, pure and impure functions are easily differentiated. This makes the code extremely readable and tidy, which is one of the most crucial aspects of coding.

Easy Debugging

The debugging process is very simple with functional programming. Since pure functions depend on the user input values, it becomes easy to monitor any mistakes. To figure out where things went wrong, all you have to do is follow the values.

For beginners, this is extremely beneficial because it makes creating programming logic much easier. Because the testing procedure is so simple, you only have to worry about problems in one specific function. You’ll know what to expect in terms of output, which will make it easier for you to find errors.

Parallel Programming

Parallelism is significantly easier to deal with when using a functional approach. This is primarily due to pure functions’ properties. Parallel programming becomes significantly easier to handle because you’ll be dealing with user input almost exclusively.

Lazy Evaluation

Functional programs only store values if it’s required. This eliminates the need for repeated evaluations, resulting in increased efficiency. This makes your program more efficient by avoiding unnecessary evaluations in programs.

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Cons of Functional Programming:

Cons of Functional Programming

Along with its pros, functional programming has its cons as well.


is the major complication concept in functional programming. It is the only method you have to implement for iteration in functional programming, as you can’t use loops. It’s not easy to understand and implement for some people. It takes some time and effort to have a proper understanding of it.

However, you’ll need to adopt an entirely new perspective and learn to think in a recursive manner. People who are used to the OOP method will find this particularly difficult because they are used to loops.

Mathematical Terminology

Many people are scared of learning functional programming because of its complicated mathematical terminology. This makes people not to touch this approach. However, it requires sufficient time and a lot of effort to understand the mathematical terminology and concepts. And many people find it quite difficult.

Still, as a software engineer, whether you like it or hate it, you could consider mathematics by your side. In a nutshell, programming and mathematics are tightly coupled together.

Object-Oriented Programming Pros and Cons

OOP helps you create instances of classes for objects. There are many programming languages that support OOP to some extent. Here are object-oriented programming pros and cons we should consider.

Pros of OOP:

Pros of Object-Oriented Programming

OOP has turned out to be the best approach for software development. Here are some major advantages of OOP.

Faster Development

Reusable elements allow faster development. Moreover, its developed code and libraries of objects in projects can also be reused for future projects.

Lower Development Cost

The nature of reusability in the project minimizes the software development cost. Object-oriented analysis and design usually receive special attention, lowering the overall development cost.

Improved Maintainability

Since the whole code part is centralized, it’s quite easy to create a maintainable procedure code. So, you can access your data anytime whenever any update is required. Also, it enhances the security of the programming.

Moreover, parts of the system can be upgraded without requiring large-scale alterations in case of issues because the architecture is modular.

Cons of OOP:

Cons of Object-Oriented programming

No language falls into the category of perfect programming language or method. Therefore, OOP also has its drawbacks. So, let’s walk through it.

Programming Complexity

Many programs don’t choose the path of OOP because of its complexity. As a result, beginners feel OOP is not easy to handle and user-friendly.

Large Program Size

When we compare OOP-enabled systems to other program-based methods, OOP-based systems consist of a bunch of code.

Slower Programs

OOPs are slower than procedure-based systems because they require more instructions to be executed.

Not an All-around Solution

Some types of programs are not suitable for OOP. Because there is no right solution that fits all types of issues, this drawback of OOP are applicable to all programming methods.

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Which One is Better? : OOP vs Functional Programming

OOP vs Functional Programming

Well, we have many solutions to real-world problems. This implies to programming world as well. And here, we have two programming paradigms for structuring and organizing your code in order to implement solutions. However, as a developer, if you know how to implement, that will give you more flexibility in problem-solving.

As OOP developers, you will claim that OOP is the appropriate approach to software development, while Functional Programming teams will claim that FP is better. As a matter of fact, both methods are essential paradigms that share the common goal of bug-free programs, but their approaches are different.

Therefore, it’s an endless debate between functional programming and object-oriented programming due to different opinions. Both programming paradigms have their advantages and drawbacks. As a result, many developers opt to use hybrid solutions to meet the needs and objectives of each project. If you are still in a dilemma of choosing any approach, we suggest you contact a top-notch software development company. They will always guide you through the whole journey of the software development process.

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Maitray Gadhavi is a senior business development manager with Radixweb who accelerates the growth of organizations through innovation-led custom software development. Balancing the long-term gains in an evolving industry, he brings the voice of the customers into the enterprise. Binge-watching favourite series is his idea of fun after work.