# functional programming

CEFR C1 · Compound

Source: https://englishreference.com/word/functional-programming
Updated: 2026-07-22

## Definition

a way of writing computer code that focuses on using math-like functions to solve problems. It avoids changing data or keeping track of the computer's 'state', which helps prevent bugs.

For teachers: a programming paradigm where programs are constructed by applying and composing mathematical functions. It emphasizes immutability and the avoidance of side effects, contrasting with imperative styles that rely on changing state.

## Examples

- Functional programming makes it easier to test small parts of your code.
- The team switched to functional programming because it helped them manage complex data transformations without introducing hidden bugs.
- By adopting functional programming principles like pure functions and higher-order logic, developers can create highly concurrent systems that are easier to reason about and maintain over time.

## Usage notes

- Typically used as an uncountable noun to describe the paradigm or style of software development.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.