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

JS Object and Inheritance

  1. Object Overview
  2. Object Type
  3. Prototype and Inheritance
  4. Create Object
  5. Object Literal Expression
  6. Create Object with Parent X
  7. Get/Set Prototype
  8. Prevent Adding Property
  9. Determine Type of Object
  10. Clone Object
  11. Test Object Equality
  12. Add Method to Prototype
  13. Object Object
  14. Object.prototype
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