JavaScript Data Types

JavaScript Data Types — a practical guide to JavaScript data types with clear examples you can reuse in real projects.

JavaScript Tutorial Series (12/101). Prefer one article? Read the complete JavaScript tutorial.

Short description

Arrays and functions are objects; null is a historical typeof quirk (`object`).

typeof examples

typeof 'hi';      // string
typeof 42;         // number
typeof true;       // boolean
typeof undefined;  // undefined
typeof null;       // object (quirk)
typeof {};         // object