Lesson 13 — Ternary & short-circuit

Small decisions on one line

The ternary operator cond ? a : b means "if cond then a, else b". Short-circuit operators skip work: a || b returns a if it is truthy, otherwise b (handy for defaults); a && b returns b only if a is truthy (handy as a guard).

const label = score >= 50 ? "pass" : "fail";
const name = input || "Guest";

"Truthy" means anything except false, 0, "", null, undefined and NaN.

Why it matters: these keep simple choices short and readable.