I remember the late 1980s when Computer Magazines were all about OOP. — Object Oriented Programming. Everything should be an object, everything was about moving that Object from one state to another. A concept, that has it‘s benefits in many cases but quite often carries a lot of complexity into programming.
In 2023 modern programming languages more often follow another (older) paradigm: Functional Programming became Avantgarde again. What does that mean?
Functional programming is a programming paradigm that focuses on building software by composing pure functions, and avoid any mutable states.
- Pure Functions: In functional programming, functions are considered pure when they have no side effects and produce the same output for the same input every time they are called. They rely solely on their input parameters to generate a result, without modifying any external state or variables.
- Immutability: Functional programming promotes immutability, which means that once a value is assigned, it cannot be changed. Instead of modifying existing data, functional programs create new data structures with the desired modifications. Immutable data structures are thread-safe and help avoid complex bugs related to shared mutable state.
- Higher-Order Functions: Functional programming languages treat functions as first-class citizens, meaning functions can be passed as arguments to other functions, returned as results, and assigned to variables. Higher-order functions are functions that operate on other functions, enabling powerful composition and abstraction techniques.
- Recursion: Recursion is a fundamental technique in functional programming. It involves defining functions that call themselves to solve a problem by breaking it down into smaller subproblems. Recursion allows for elegant solutions to certain types of problems and is often used instead of iterative loops.
- Avoidance of Mutable State: Functional programming discourages the use of mutable state, such as global variables or objects that can be modified after creation. By minimizing mutable state, programs become easier to reason about, test, and parallelize. Instead, functional programs emphasize using pure functions and immutable data structures.
- Declarative Style: Functional programming favors a declarative programming style, where you describe “what” you want to achieve rather than specifying “how” to achieve it through detailed step-by-step instructions. This leads to more concise and expressive code that focuses on the problem domain rather than implementation details.
- Composition: Functional programming encourages the composition of small, reusable functions to build complex behavior. By combining functions together, you can create new functions that perform more advanced operations. Function composition enables code reuse, modularity, and maintainability.
- Data Transformation: Functional programming emphasizes transforming data from one state to another, rather than modifying data in place. This approach helps in building pipelines or sequences of functions that transform input data into the desired output format.
