ActionScript for Flash MX: The Definitive Guide, Second Edition

Object.registerClass() Class Method

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Alphabetical Language Reference

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See Also

instanceof, Object.__proto__; Chapter 12

Object.__proto__ Property

a reference to the object’s constructor’s prototype property

Flash 5

read/write

someObject.__ proto__

Description

The __proto__ property stores a reference to the automatically-assigned prototype prop-

erty of someObject’s constructor function, which is used to transfer properties down

through a class hierarchy. An object’s

__proto__ property is mostly used internally by the

interpreter to look up inherited properties for an object, but we can also use it to deter-

mine the class of an object, as shown in Example 12-5. Some developers also use

__proto__

to establish inheritance between a subclass and its superclass, as discussed in “Advanced

Issues with Standard SuperClass Assignment” in Chapter 12.

Note that the __proto__ property is formed using two underscore

characters at its beginning and another two underscore characters at

its end.

Usage

Overwriting an object’s __proto__ property is not recommended, because it alters the

natural structure of class inheritance.

See Also

Function.prototype, instanceof; “The __proto__ property,” in Chapter 12

Object.registerClass() Class Method

assign a constructor for a movie clip symbol

Flash 6

Object.registerClass( ...