Which paradigm focuses on solving problems by composing pure functions and avoiding shared state?

• A. Functional Programming
• B. Object Oriented Programming
• C. Imperative Programming
• D. Concurrent Programming

Answer: (A)

Focusing on solving problems by composing pure functions and avoiding shared state is the hallmark of functional programming. In this approach, functions are designed to be pure: given the same inputs, they always return the same outputs and produce no side effects. This predictability, called referential transparency, makes it easier to reason about code, test it, and debug it.

Programming is done by building small, simple functions and combining them to form more complex behavior. Data is typically immutable, so instead of modifying an existing value, you create new values from existing ones. This reduces bugs from unintended interactions and makes it safer to run things in parallel, since there aren’t hidden, changing shared pieces of data.

Other paradigms don’t center on these ideas. Object-oriented programming emphasizes objects that encapsulate state and behavior; imperative programming focuses on a sequence of commands that mutate state; concurrent programming is about executing tasks simultaneously, which can be used within various paradigms but isn’t defined by the practice of composing pure functions and avoiding shared state.