JavaScript: Boolean Object

By Xah Lee. Date: 2014-09-24. Last updated: 2020-06-27.

Boolean is the value of the property key "Boolean" of the Global Object .

console.log( window.Boolean === Boolean ); // true

Type

Type of Boolean is a function.

console.log( typeof Boolean === "function" ); // true

Parent of Boolean is Function.prototype. [see Prototype and Inheritance]

console.log( Reflect.getPrototypeOf ( Boolean ) === Function.prototype ); // true

Purpose of Boolean is:

Implicitly called by JavaScript to convert value to true or false. example: in a if statement.
Implicitly called by JavaScript to convert true or false to string, by first converting the value to boolean object, then use method toString.
Has the property key "prototype" that holds valueOf and toString methods.