JavaScript Boolean prototype Constructor

## JavaScript Reference

Overview

## JavaScript Objects

JS Array JS Boolean JS Date JS Math JS Number JS String JS RegExp JS Global

## Browser Objects

Window Navigator Screen History Location

## HTML DOM Objects

DOM Document DOM Elements DOM Attributes DOM Events

## HTML Objects

DOM Anchor DOM Area DOM Base DOM Body DOM Button DOM Form DOM Frame/IFrame DOM Frameset DOM Image DOM Input Button DOM Input Checkbox DOM Input File DOM Input Hidden DOM Input Password DOM Input Radio DOM Input Reset DOM Input Submit DOM Input Text DOM Link DOM Meta DOM Object DOM Option DOM Select DOM Style DOM Table DOM td / th DOM tr DOM Textarea

# JavaScript Boolean prototype Constructor

JavaScript Boolean Object

## Example

Make a new method for the Boolean object:

Boolean.prototype.myColor=function()
{
if (this.valueOf()==true)
{
this.color="green";
}
else
{
this.color="red";
}
}

Make a Boolean object, then calls the myColor method:

var a=new Boolean(1);
a.myColor();
var b=a.color;

The value of b is now:

green
Try it yourself »

## Definition and Usage

The prototype constructor allows you to add new properties and methods to the Boolean() object.

When constructing a property, ALL booleans will be given the property, and it's value, as default.

When constructing a method, ALL booleans will have this method available.

Note: Boolean.prototype does not refer to a single boolean, but to the Boolean() object itself.

Note: Prototype is a global object constructor which is available for all JavaScript objects.

## Browser Support

The prototype property is supported in all major browsers.

## Syntax

Boolean.prototype.name=value

JavaScript Boolean Object

## Your suggestion:

Your E-mail (optional):

Page address:

Description:

Close [X]

## Thank You For Helping Us!

Your message has been sent to W3Schools.

Close [X]
Search w3schools.com:

## WEB HOSTING

Best Web Hosting UK Reseller Hosting Wow! $5 SSD Hosting

## WEB BUILDING

Download XML Editor
FREE Website BUILDER FREE Website Creator

## WEB RESOURCES

Web Statistics Web Validation

## SHARE THIS PAGE