 | JavaScript | |||
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| JavaScript syntax: | - | myBoolean = BooleanValue | |||||||
| - | myBoolean = new Boolean() | ||||||||
| - | myBoolean = new Boolean(aValue) | ||||||||
| Argument List | BooleanValue | A Boolean value (either true or false) | |||||||
| aValue | A value to be converted to a Boolean object. | ||||||||
| Object properties: | constructor, prototype | ||||||||
| Object methods: | toSource(), toString(), valueOf() | ||||||||
An instance of the class "Boolean" is created by using the new operator on the Boolean() constructor. The new object adopts the behavior of the built-in Boolean prototype object through the prototype-inheritance mechanisms.
All properties and methods of the prototype are available as if they were part of the new instance.
A Boolean object is a member of the type object and is an instance of the built-in Boolean object.
Cloning the built-in Boolean object creates Boolean objects is done by calling the Boolean() constructor with the new operator. For example:
myBoolean = new Boolean(true);
A Boolean object can be coerced into a Boolean value and can be used anywhere that a Boolean value would be expected.
Programmers familiar with object-oriented techniques may be happy to use the Boolean object, while procedural language programmers may prefer to implement the same functionality with a Boolean value instead.
This is an example of the flexibility of JavaScript in its ability to accommodate a variety of users from different backgrounds.
The prototype for the Boolean prototype object is the Object prototype object.
| See also: | Boolean.prototype, Native object, Object object, unwatch(), watch() |
| Property | JavaScript | JScript | N | IE | Opera | NES | ECMA | DOM | CSS | HTML | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| constructor | 1.1  | 3.0 | 3.0 | 4.0 |  | | 2 | | | | - |
| prototype | 1.1 | 3.0 | 3.0 | 4.0 | 3.0 | 2.0 | 2 | | | | - |
| Method | JavaScript | JScript | N | IE | Opera | NES | ECMA | DOM | CSS | HTML | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| toSource() | 1.3 | | 4.06 | | 3.0 | | | | | | - |
| toString() | 1.1 | 3.0 | 3.0 | 4.0 | 3.0 | 2.0 | 2 | | | | - |
| valueOf() | 1.1 | 3.0 | 3.0 | 4.0 | | | 2 | | | | - |
ECMA 262 edition 2 - section - 4.3.15
ECMA 262 edition 2 - section - 10.1.5
ECMA 262 edition 2 - section - 15.6
ECMA 262 edition 3 - section - 4.3.15
ECMA 262 edition 3 - section - 15.6
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| Boolean literal | Up | Boolean() |
JavaScript Programmer's Reference, Cliff Wootton Wrox Press (www.wrox.com) Join the Wrox JavaScript forum at p2p.wrox.com Please report problems to support@wrox.com © 2001 Wrox Press. All Rights Reserved. Terms and conditions. | ||