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functional programming

Pure Functions

A pure function always returns the same output for the same input and produces no side effects — it doesn't modify external state, call APIs, or write to the console. Think of a pure function like a vending machine: put in the same coins and press the same button, and you always get the same snack. Pure functions are the foundation of functional programming because they are predictable, easy to test, and safe to run in parallel.

Use Cases

  • •Data transformation pipelines where each step must be predictable and testable
  • •Memoization and caching strategies that rely on referential transparency
  • •Concurrent or parallel computation where shared mutable state would cause race conditions
  • •Unit testing without complex setup or mocking of external dependencies

Implementation

Output

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