There are some reservations for functional programming. In this article, you will learn how and in what environment this paradigm can improve software comprehension, testability, and stability.

What is functional programming?

The answer to this question is often found in the expert literature, which is underlined in math examples and has many more or less comprehensible explanations. However, the aspects that are really relevant to software development can be explained in one simple sentence. Functional programming is the writing of software from pure functions.

A pure function is a completely normal program function with only two special properties.

– If the input parameters are the same, the same return value is always returned.
– No Side Effects

What are the benefits of functional programming?

The concept of pure functions is not only relatively easy to explain, but it also describes software that is really easy for developers to understand because individual functions are independent and can be written, understood, and tested independently. I will be able to do it. This is a big advantage.

However, much of the software written today follows another paradigm of object-oriented models (OO models) that propagate in the opposite direction. In the object-oriented world, functions are called methods and are encapsulated by objects (classes) along with related data. When the method is called, you can access the input parameters passed and the data in the object itself. The state of the object is consciously manipulated using the appropriate methods. H. The data in the object itself changes. In addition, the object’s data is passed to other objects as the return value of the method call, where it is further manipulated.

What is functional programming suitable for?

The benefits of functional programming are clear, especially when compared to object-oriented programming. However, in practice, it is usually not possible to develop a complete software system in a purely functional way. There are always areas of source code where common conditions and side effects play an important role. When a software system communicates with its environment, for example sending data over a database, file system, or network, the pure functional paradigm is completely inappropriate.

Functional programming using the JAVASCRIPT example

JavaScript is one of the most popular programming languages ​​today and is the standard language for web development. Originally object-oriented, it meets all the requirements for use as a functional language. Especially since version 6 (standardized as ECMAScript 6), JavaScript offers developers many possibilities for efficient and functional programming. The next section uses the most common functional programming patterns in JavaScript as an example.


The purpose of functional programming is to make the software development process simple and easy to understand for the developers involved. Due to educational background and the use of unique terminology, there is still a great deal of prejudice against certain applicability in software development projects. Functional programming is the creation of pure functions. Once the meaning of this basic idea has been understood and internalized by the developer, the necessary techniques and skills for applying functional programming can be learned relatively easily. If the challenge of developing suitable parts of a software functionally is accepted, the advantages in terms of comprehensibility. See for more social news aggregation, web content rating, and discussion website.