ActionScript: The Definitive Guide

Name

Boolean Class — wrapper class for primitive Boolean data

Availability

Flash 5

Constructor

new Boolean(value)

Arguments

value

An expression to be resolved and, if necessary, converted to a Boolean value, then wrapped in a Boolean object.

Methods

toString( )

Convert the value of a Boolean object to a string.

valueOf( )

Retrieve the primitive value of a Boolean object.

Description

The Boolean class creates a Boolean object which contains a primitive Boolean value in an inaccessible, internal property. Boolean objects are used purely for the sake of manipulating and examining primitive Boolean values using methods of the Boolean class. A Boolean object is, hence, known as a wrapper object because it simply packages a primitive Boolean value, giving it some object-like methods. Compare the Boolean class with the String and Number classes, which similarly wrap string and number primitive values, but with more useful results.

For the most part, Boolean objects are used internally. They are created automatically by the interpreter whenever a method is invoked on a primitive Boolean value and are deleted automatically after each use. We can create Boolean objects ourselves using the Boolean constructor, but there is seldom reason to do so.

Usage

Note that in practice it is much more common to use the Boolean( ) global function as a datatype-conversion tool than it is to use the Boolean class.

See Also

Boolean( ) global function; “The Boolean Type” in Chapter 4