Operators

Arithmetic & comparison

Standard math operators plus ** for exponents, and six comparison operators.

console.log(2 ** 10);          // 1024
console.log(10 % 3);           // 1
console.log(5 > 3 && 2 < 4);   // true

Logical short-circuiting

&& and || return one of their operands, not just true/false — used to pick fallback values.

const name = "" || "Guest";   // "Guest"
const user = { age: 0 };
const age = user.age ?? 18;   // 0, not 18!

?? vs ||

?? (nullish coalescing) only falls back on null/undefined; || also falls back on 0, "", false — a common bug source.