What is Functional Programming?

Functional programming is a programming model that emphasizes using functions to solve problems. It is based on an idea that a program can be viewed as a set of processes which transform data rather than in the form of instructions that specify a sequence of actions.

Functions can be supplied as inputs to other parts and returned as values in functional programming since they are regarded as first-class citizens. Hence, it is possible to create higher-order functions or those that interact with other parts.

Functional programming languages typically support the following features:

Immutable data: In functional programming, data is typically treated as immutable, meaning that it cannot be modified once it is created. This makes it easier to reason about the behaviour of a program and helps to prevent unintended side effects.

Recursion: Recursion is a technique for solving many problems by breaking them down into simpler and smaller subproblems and solving each subproblem recursively. It is a common technique in functional programming.

Pure functions: Pure functions are those that have no side effects and always return the same output for a given input. They are an essential concept in functional programming, as they are easier to test and debug and can be composed to create more complex programs.

Functional programming has been used to solve many problems, including data processing, concurrency, and parallelism. It is often used in combination with other programming paradigms, such as object-oriented programming or imperative programming. Some popular functional programming languages include Lisp, Haskell, and ML.