28. Functional programming

Functional programming is a programming paradigm that treats computation as an evaluation of mathematical functions and avoids changing state and changing data. In other words, functional programming promotes the application of functions, unlike imperative programming, which emphasizes changes in program state.

Functional programming has its roots in lambda mathematics, a system developed in the 1930s to investigate functions and their applications. However, it only became a practical programming discipline with the development of Lisp in 1958.

In functional programming, functions are first-class citizens. This means that functions can be passed as arguments to other functions, returned as values ​​from other functions, and assigned to variables. This is a powerful concept that allows programmers to write more concise and expressive programs.

An important feature of functional programming is immutability. In functional programming, once a value is assigned to a variable, that value cannot be changed. This contrasts with imperative programming, where variable values ​​can change over time. Immutability can make code more predictable and easier to understand and debug.

Another fundamental concept in functional programming is recursion. Since functional programming avoids changing state and using loops, recursion is often used as the main method of repetition. A recursive function is a function that calls itself until a stopping condition is met.

Functional programming also emphasizes lazy evaluation, which is evaluating expressions only when their value is needed. This can lead to more efficient code as it avoids evaluating expressions that are not needed for the final result.

There are several programming languages ​​that support the functional paradigm, including Lisp, Haskell, Erlang, Clojure, and Scala. Many other languages, such as Python, JavaScript, and C#, also incorporate functional programming elements.

Functional programming is particularly useful in situations where accuracy, conciseness, and predictability are important. This includes areas such as data analysis, machine learning, concurrent and parallel programming, and distributed systems development.

Despite its advantages, functional programming can be challenging to learn, especially for programmers accustomed to the imperative paradigm. However, with practice and study, functional programming can become a valuable tool in a programmer's arsenal.

In conclusion, functional programming is a programming paradigm that emphasizes the application of functions and avoids changing state and changing data. While it can be challenging to learn, it offers many benefits, including more concise, predictable, and efficient code. Whether you're an experienced programmer looking to expand your skills or a novice looking to learn a new paradigm, functional programming is worth exploring.

Next page of the Free Ebook:

29Design patterns

3 minutes