Boolean Values

A boolean is a value that's either true or false, always lowercase in JavaScript. Booleans are what conditions and comparisons are built from.

const isRaining = true;
console.log(5 > 3);        // true
console.log(5 === "5");    // false — different types never equal with ===

Common mistakes

• JavaScript treats several non-boolean values as "falsy" in a condition — 0, "", null, undefined, and NaN all act like false. Everything else (including "0" and []) is "truthy."