10 Functional Programming Languages for Web App Development in 2020

10 Functional Programming Languages for Web App Development in 2020

What Are The Top Functional Programming Languages for Web App Development in 2020? In this article, you'll see a list of top 10 high-level functional programming languages for web App Development in 2020

Programming complexity is always a challenge when you translate a real-world problem into a simpler or elegant solution that requires deeper understanding. These programming complexities have surely confused developers all around the world.

Ideally, every programmer should possess the basic knowledge of programming languages that are close to the system (C, GO, or C++), a language that’s object oriented ( Java and Python), a functional programming language (Scala), and a powerful scripting language ( Python and JavaScript).

The ever growing list of programming languages and protocols have made it tough for programmers and developers to choose the one that is most suitable for the project at hand.

There are several programming languages to choose from, but one of the easiest ways to select a programming language is to choose the most popular one. Python, without fail, is one of the most popular coding languages. Nearly all coders have an insatiable thirst for exploring programming languages that are gaining an edge over others. Hence, to keep further confusion at bay, I bring you the top functional programming languages for the year 2020.

Top Functional Programming Languages for Web App Development in 2020

Here’s a list of top high-level functional programming languages for web App Development in 2020:


Let’s begin by talking about the most popular language, Python. Python is a high-level programming language used for web app development, analyzing and computing data for scientific and numeric fields, creating desktop GUIs, and software development.

Python is the most common language taught at the secondary and college level due to the fact that it has numerous real-world applications.

If there is one programming language that developers should learn for web app development, then it has to be Python because it is easy to learn and has great readability.

Doesn’t it look exciting? If not, then have a closer look at some of the apps developed in Python:

Ubuntu Software Center
World of Tanks (I’m sure you have played it)

Python comes in with a lot of capabilities to create any kind of web application. It is one of the easiest programming languages that has been going around in the technology circuit.

Key Features of Python are as follows:

  • Processed at runtime by the interpreter
  • Object-oriented language
  • Easy-to-learn and master
  • Interactive language
  • Easy-to-read
  • Scalable
  • Supports GUI applications
  • Runs on Windows, Mac, Unix, and Linux

Functional Programming In Python:

Without any special Python features or libraries, you can start coding in a more functional way.

Let me show with the help of a code snippet on how Functional Programming works in Python:

Pure Functions:

Let’s create a Pure Function to multiply numbers by 2.

The original list of numbers are unchanged and you don’t have to refer to any other variable outside of the function, so its pure.

However, you need to consider that the creator of Python didn’t intend Python to have functional features, but he did appreciate that some of the benefits of its introduction has brought to Python. As a result the language implementation have not been optimized for functional programming.


Java is the most used web app development programming language.

Java has been the most searched functional programming language as per Google. Java has currently saved the number two spot with over 19.52%. Java is one of the most suitable high-level programming languages as it runs majorly on all the platforms.

Java is used to develop Android, Server, Web, Scientific, and Gaming Apps.

Some of the popular Java applications are:

ThinkFree cloud office

NASA world wind

Blu-ray Disc Association


Key Features of Java are as follows:

  • Object-oriented language
  • It runs on all the platforms
  • Supports APIs that make integration a seamless process
  • It is easy-to-learn and read
  • Hundreds of open source libraries available
  • Easy to get expert help from Android communities
  • Powerful IDEs make coding easy and error-free

Functional Programming with Pure Functions In Java:

A pure function is a functional programming that depends only on its input arguments and no external state.

Let’s take an example of a code snippet to show the working paradigm of Pure Functions in Java:

In the code snippet above, calculateBonus2() is a pure function as it obeys both requirements for purity.

Run script1.js as follows:

Here's the output you should observe:

In this code snippet, you might have learned the basics of core function in functional programming in Java.


Hypertext Preprocessor or better known as PHP is a server-side scripting open-source language. Curated byZend Technologies in 1995, it was specially developed for websites but it’s generally used for web development today.

Apart from server-side scripting, it is used for command-line scripting and coding applications. PHP is primarily a coding language used for creating dynamic websites but you can also create Android and iOS Apps in PHP.

It has been stated that PHP is one of the most popular programming languagesthat can be used in the development of E-commerce & dynamic websites along with the development of mobile applications.

Key Features of PHP are as follows:

  • Open-source
  • Independent of platform
  • Uses procedural and object-oriented
  • Easy-to-learn
  • Numerous applications and uses
  • Server compatibility
  • Easy database integration

Functional Programming In PHP:

PHP is not entirely functional, however PHP developers can work around the way they program in a functional way. Developers can start applying these simple approaches that can make their code simpler, much more readable, testable with fewer side effects.

Let’s look at the coding instance that can change the way you code in PHP:

Suppose you want to get a file into an array. In this scenario, you will use HTTP to get

It reads the content from an external site ( external input) and shows the result to the console (external output). Can you imagine a functional code change here? Sure, let’s do it by slicing the above code:

The result is just the same but now you can see an impure function (getFilecontent) which can easily be mocked in the code sample whereas a Pure Function(formatLines), always return the same output which is easy to unit test.


Scala is a general purpose, high-level multi-paradigm functional programming language. It combines the feature of object-oriented and functional programming in one concise. Scala stands for scalable language.

Scala is highly influenced by Java as it provides Javascript runtimes. It lets you build high-performance systems with easy access to huge ecosystem of libraries.

Key Features of Scala are as follows:

Type inference

Singleton object


Lazy computation

Concurrency control

Functional Programming in Scala:

Functional Programming in Scala is a way of writing software applications using only Pure Functions and Immutable Values.

Pure Functions in Scala:

Let’s take an instance of two Pure Functions add and multiply, where each of these functions takes two values and returns the sum and product of the values respectively. Since, these functions are pure, the following two sequences of calls will result in the same outcome:

Expressions that use Pure Functions can be easily rearranged and yield themselves for better optimization that produce the same result.

C++ :

C++ also pronounced as C Plus Plus, is an object-oriented high-level programming language with low-level memory manipulation features. C++ inherits its syntax from C and it is an extension of C but C++ is more comprehensive than C.

The demand for C++ developers have always been there and it is not just about developing mobile/web applications, rather than developing it has been one of the most dominant languages, used in all sectors ranging from finance to manufacturing to banking and several others.

C++ has been used exceptionally to develop cross-platform mobile apps through its unified debugging experience and powerful environment. Some of the popular tools developed under the technical norms of C++ are Google Chrome, Amazon, PayPal, World of Warcraft, Photoshop, and many others.

It can be used to develop Gaming applications, Enterprise Tools, Computation Platforms, Web Browsers, etc.

Key Features of C++ are as follows:

  • It is simple and efficient
  • Object-oriented
  • Massive library
  • Portable
  • Extremely fast

Functional Programming in C++:
Pure Functions are quite similar to mathematical functions. In the following code snippet, I have used a function, a meta-function, and a constexpr function. All three are pure functions.

Although, these functions are different but they are producing the same output. powFunc (line 5 - 8) is a classical function. It will be executed at the run time of the program and can get non-constant arguments. In contrary, PowMeta (line 10 - 18) is a meta-function which is executed at compile time of the program. Therefore, PowMeta needs constant expressions as arguments. The constexpr function powConst (line 20 - 24) can run at compile time and at run time. To be executed at the compile time, powConst needs - accordingly to the meta-function PowMeta - constant expressions as arguments.


Javascript is a high-level interpreted programming language. It is a multi-paradigm language that supports object-oriented and functional programming. Javascript can be used to develop and control web pages.

It is possible to create mobile/web applications with Javascript but it has to be used with CSS, HTML, and AJAX.

There are several web frameworks that can be used to create a Javascript App such as PhoneGap, jQueryMobile and Ionic.

Creating mobile/web apps in Javascript is easier as you have to code once that can be released on multiple platforms such as Android, iOS, and Windows.

Key Features of JavaScript are as follows:

  • Can be learned in a few days
  • Fast and efficient
  • Used for creating animations

Functional Programming In JavaScript:
Pure Functions are pillars of functional programming. A pure function doesn’t depend on and doesn’t modify the state of variables out of its scope.

Here’s a code snippet below to showcase the implementation of Pure Functions in Javascript:


Objective-C is a high-level programming language derived and inherited from C. It is one of the core programming languages used by Apple for iOS development prior to Swift.

Though Swift is replacing Objective-C, the queries at StackOverflow show that app developers are working on Objective-C. You can create all kinds of applications through Objective C.

Key features of Objective-C are as follows:

  • Simple to use
  • Use C++ and C while using Objective-C
  • It uses dynamic run-time
  • It supports dynamic typing
  • Works smoothly with Apple Inc

Functional Programming in Objective C:

This is a really simple function, It takes a URL on the disk and tells if it is expired or not. The code represents the validation of File expiry through the series of statements and functions.


Ruby is a general-purpose object-oriented programming language. Curated by Yukihiro Matz Matsumoto in the 1990s, it supports multiple paradigms.

It is the fastest-growing programming language. Ruby holds the second spot with most of the projects completed followed after Java.

By using a web framework such as RubyMotion or Rhodes, you can create applications for Android, iOS, and Windows.

Some of the popular websites developed in Ruby are Fiverr, Airbnb, Pixlr, Groupon, Basecamp, Scribd, Bloomberg, ThemeForest, and many others.

Key features of Ruby are as follows:

  • It supports dynamic typing
  • Object-oriented language
  • Easy coding. Anyone can do it
  • Best for beginners
  • Use existing codes
  • Helpful community

Functional Programming in Ruby:
Let’s try and understand by taking an example, In the code snippet below, I want to find out if all the elements in the array that are different from the first element.

To make this work I need to remove the first element from the array & at the same time save this element so we can compare it against the rest.

I am trying to work with the array and if you take a closer look at the list of available methods, I have found that Array#shift method does exactly what I want.

Let us look at the value of arr after calling the method once:

Did you notice any difference? The array lost one element i.e number 1 and I didn't notice. That’s how these mutability bugs can produce erroneous results.

Fixed Version is as follows:


A combination of two languages ( Perl 5 and Perl 6) can be used to define Perl as a programming language. It is a high-level functional programming language.

Perl 5 and Perl 6 both run and evolve independently without support. Perl is used for a lot of applications such as automation, bioinformatics, website development, app development, games development, and others.

A few of the examples of popular websites developed in Perl are LiveJournal, IMDB, and Booking.

Key Features of Perl are as follows:

  • It is fast, reliable, and personal
  • It is fun. Perl has the happiest users
  • Learning Perl will end up you in low competition space

Functional Programming in Perl:
Perl has a built-in function, map, which takes arguments as a code block and an array. For each item in the array, the code block is called, with the value of Perl’s default variable, $, set to that item. The code block can do whatever it wants to with the item, and return something that becomes a corresponding item in the new array.

The code snippet below represents the same:

The script: foo.pl

To run it from a computer install Perl:

The output from the Perl script is as follows:


SQL, also known as Structured Query Language is a domain specific and functional programming language used in application development to enable a programmer to work with data. It is a bit more different than C++, hence SQL is better known as a declarative language.

Functional Programming in SQL:

To explain, functional programming in SQL, let us take an example to compute the last Friday of the Month. Let’s begin the computation through the sample code snippet shown below:

This Select expression can be easily converted into an inline function, for which @date is the parameter. From then it can be directly used into Updates, Selects or Deletes, which preserves the highly desired goal to do business logic in set based operations.

Here’s a snippet for T-SQL, functional programming example, in which variables, loop or if statement are not needed.

From that function, it can be made easy to Update on a table named Calendar, for which I want to set vacation flag to 1 to every Friday of every month using the function to find out which date is a friday.

I am doing only functional programming here, since only read-only variables, and no explicit loop, are used into the algorithm. A mix of CTE, Inline function, and natural looping between rows that SQL does help to achieve these requirements.


Yes, you read it right, these are the top programming languages that you can look forward to the year 2020. These are the top functional programming languages that can redefine and reshape the future of programming sooner or later.

The ultimate choice is yours to select a programming language that can help you out in your project pursuits.

Why I use Java? Why not C#, JavaScript, or Python?

Why I use Java? Why not C#, JavaScript, or Python?

In this article, you'll see some reasons to I learn and use Java, why not C#, JavaScript, or Python? and why Java is one of the best programming language

But why Java? Why not C#, JavaScript, or Python?

Well… there were a few well-thought reasons behind this decision.

The top 3 programming languages in the world right now are Python, Java, and JavaScript. Sorry my C# friends, C# is not in the top 3 list. I’ll talk about C# later in this post.

Why not JavaScript?

Yes, we can do object-oriented programming with JavaScript. But let’s be real. Object-oriented programming with JavaScript is a bit messy. JavaScript classes are not real classes. They are syntactic sugar over constructor functions. Also, in JavaScript, we don’t have access modifiers like public and private. Yes, we can achieve them using other ways and I’ve demonstrated that in my Object-oriented Programming with JavaScript course. But still, JavaScript is not the best language for object-oriented programming.

Why not Python?

Python is a great language. I love it! It’s free of clutter and is simple to use. It also has better support for OOP features. So, why didn’t I choose Python? Because based on my research, Python is often used among people in the data science community, rather than professional software engineers.

Yes, you we use Python to build desktop and mobile apps as well as backends. However, Python is not the language of choice for building mobile or desktop apps. These days, the majority of people are building mobile apps using cross-platform solutions such as React Native or Flutter. Others do native development in Java (for Android) or Swift (for iOS). The same applies to building desktop applications with Python. Python is not very well known for that reason.

Why not C#?

C# and Java are very similar in terms of syntax and they both have great support for OOP features. So, why didn’t I choose C# given that I have several C# courses?

Well… I looked at different sources to see the popularity of Java vs C#. Google Trends is a great resource. As you saw earlier in the post, Java is way more popular than C#. Does it mean it’s a better language? Well, it depends on _how _we define “better”.

What is better? A Ferrari or a truck? It depends on what you want to do. Ferrari is a super-fast car but it’s useless if you want to use it to move house. Programming languages are the same. There is no such thing as the best programming language. Every language has pros and cons. C++ is well known for its speed. Python is popular for its simple and clean syntax as well as tons of resources for machine learning.

Just because Java is more popular, it doesn’t mean it’s a better language than C#. In my opinion, C# is a more feature-rich language but Java was marketed better.

C# and Java have been rivals since day one. Many of the features we’ve had in C# for a long time were introduced in Java years later. Some features don’t exist to this day! For example, in Java, we don’t have optional parameters which are very handy. We have to overload a method. Ugly! Jave interfaces are also bad.

I personally prefer C#. But as I said, Java has had better marketing and that’s why it’s always been more popular than C#.

Why Java?

So, I chose Java because it’s used more widely than C# amongst professional software engineers. There are more Java developers out there than C# developers. Most universities and colleges also tend to teach Java, rather than C#.

Now, all that aside, C# and Java are very similar in terms of the syntax. Recently I posted this tweet asking my students if this is Java or C# code?

The reality is I wrote this code in IntelliJ (a popular Java IDE). But the code is valid C# and Java code. Someone argued that this is an over-simplified example and shouldn’t be used as a basis for comparison. That is true. But my whole point is that if you understand this code, you can perfectly take my Data Structures or Design Patterns courses.

What You Should Take Away

In my opinion, Java in the programming world, is like the English language in the world we live in. If Italian or Hindi is the only language you speak, you’re probably not gonna get very far ahead.

If you understand English, you have access to tons of valuable resources. Whether you want to learn programming, or painting, or piano, if you “understand” English, you have tons of resources in front of you. You don’t need to be fluent in speaking English. All you need is to just understand it.

It’s the same story with Java. There are tons of great programming books written and these books use Java. If you simply understand the Java syntax, you can take advantage of these amazing resources. You don’t need to become a Java developer and let go of your favorite language, whether it is C# or JavaScript or Python or PHP.

Java vs JavaScript: Difference between Java and JavaScript

Java vs JavaScript: Difference between Java and JavaScript

The video on Java vs JavaScript provides you with a short and crisp description of the two programming languages. You will also see the head to head comparison between the two on various aspects and learn the similarities and differences between them.

Java vs JavaScript: Difference between Java and JavaScript 

The video on Java vs JavaScript provides you with a short and crisp description of the two programming languages. You will also see the head to head comparison between the two on various aspects and learn the similarities and differences between them.

Thanks for reading

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