Lesson 22 — Compose & pipe (expert)

Build pipelines from small functions

pipe(f, g, h) creates a function that sends a value through f, then g, then h — each one gets the previous result. compose is the same but right-to-left. You can build pipe with reduce: start with the input value and apply each function in turn.

const shout = (s) => s.toUpperCase();
const excite = (s) => s + "!";
console.log(excite(shout("hi"))); // HI!  — pipe(shout, excite)("hi")

Why it matters: data cleaning and transformation code becomes a readable list of steps.