JavaScript fuzzy meaning of constructor (2026)

By Xah Lee. Date: .

JavaScript no exact meaning of “constructor”

the JavaScript circus. the term “constructor” doesn't really have a exact meaning.

BigInt and Symbol are not constructors, they return primitives not objects, and they cannot be called with the new operator. But Iterator is, but cannot be called.

ECMAScript 2026 describes constructor as

function object that creates and initializes objects

Iterator is typeof function, but is not callable, nor does it initialize objects.

ECMAScript constructor 2026-09-27 19790 ll
ECMAScript constructor 2026-09-27 19790 ll