What You'll Learn

Function composition is the process of combining two or more functions to create a new function. It's one of the most powerful patterns in functional programming, allowing you to build complex operations from simple, reusable building blocks.

Learning Objectives

  • Understand function composition and why it matters
  • Implement compose and pipe utilities
  • Build data transformation pipelines
  • Use point-free style programming
  • Compose async functions
  • Apply composition in real-world scenarios
Duration: 5-7 minutes
Level: Intermediate to Advanced
Prerequisites: Strong JavaScript fundamentals, understanding of higher-order functions, arrow functions

Why Learn Function Composition?

Function composition helps you:

  • Write cleaner code - Break complex logic into simple, testable functions
  • Improve reusability - Small functions can be combined in different ways
  • Enhance readability - Pipelines read like a series of transformations
  • Reduce bugs - Pure functions are easier to test and debug
  • Think declaratively - Focus on what to do, not how to do it

What You'll Build

In this tutorial, you'll implement:

  • compose and pipe utility functions
  • Data transformation pipelines
  • Point-free style functions
  • Async composition utilities
  • Real-world examples: data processing, validation, API transformations

Tutorial Structure

This tutorial covers:

  • Composition Basics - Combining functions right-to-left
  • Pipe - Combining functions left-to-right
  • Point-Free Style - Writing functions without mentioning arguments
  • Currying for Composition - Making functions composable
  • Async Composition - Composing promises and async functions
  • Real-World Patterns - Data pipelines, validation chains, transformations