JS: Boolean Object

By Xah Lee. Date: . Last updated: .

Boolean is the value of the property key "Boolean" of the global object. [JS: the Global Object]

console.log( window["Boolean"] === Boolean ); // true

Type

Boolean is a function.

[see JS: Value Types]

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

Parent

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

// parent of Boolean
console.log ( Object.getPrototypeOf ( Boolean ) === Function.prototype ); // true

Purpose

Purpose of Boolean is:

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

[see JS: true, false]

Boolean Constructor

[see JS: Boolean Constructor]

Properties

Reference

ECMAScript® 2016 Language Specification#sec-boolean-constructor

Boolean Topic

  1. JS: true, false
  2. JS: Boolean Object
  3. JS: Boolean.prototype

Object and Inheritance Topic

  1. JS: Object Overview
  2. JS: Object Type
  3. JS: Prototype and Inheritance
  4. JS: Create Object
  5. JS: Object Literal Expression
  6. JS: Get/Set Prototype
  7. JS: Create Object with Parent X
  8. JS: Prevent Adding Property
  9. JS: Determine Type of Object
  10. JS: Clone, Deep Copy Object/Array
  11. JS: Test Equality of Objects
  12. JS: Object Object
  13. JS: Object.prototype
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