flash.utils.Dictionary - Adobe® Flex® 4 Language Reference (Flex 4)

Package	flash.utils
Class	public dynamic class Dictionary
Inheritance	Dictionary Object

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9

The Dictionary class lets you create a dynamic collection of properties, which uses strict equality (===) for key comparison. When an object is used as a key, the object's identity is used to look up the object, and not the value returned from calling toString() on it. Primitive (built-in) objects, like Numbers, in a Dictionary collection behave in the same manner as they do when they are the property of a regular object.

The following statements show the relationship between a Dictionary object and a key object:

 var dict:Dictionary = new Dictionary();
 var obj:Object = new Object();
 var key:Object = new Object();
 key.toString = function() { return "key" }
  
 dict[key] = "Letters";
 obj["key"] = "Letters";
  
 dict[key] == "Letters"; // true
 obj["key"] == "Letters"; // true 
 obj[key] == "Letters"; // true because key == "key" is true because key.toString == "key"
 dict["key"] == "Letters"; // false because "key" === key is false
 delete dict[key]; //removes the key

Important:The Dictionary class is only available to ActionScript 3.0 code (running in SWF content). It is not available to JavaScript code (running in Adobe^® AIR™).

See also

=== (strict equality)

Public Properties

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	Property		Defined By
		constructor : Object A reference to the class object or constructor function for a given object instance.	Object
		prototype : Object [static] A reference to the prototype object of a class or function object.	Object

Public Methods

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	Method		Defined By
		Dictionary(weakKeys:Boolean = false) Creates a new Dictionary object.	Dictionary
		hasOwnProperty(name:String):Boolean Indicates whether an object has a specified property defined.	Object
		isPrototypeOf(theClass:Object):Boolean Indicates whether an instance of the Object class is in the prototype chain of the object specified as the parameter.	Object
		propertyIsEnumerable(name:String):Boolean Indicates whether the specified property exists and is enumerable.	Object
		setPropertyIsEnumerable(name:String, isEnum:Boolean = true):void Sets the availability of a dynamic property for loop operations.	Object
		toLocaleString():String Returns the string representation of this object, formatted according to locale-specific conventions.	Object
		toString():String Returns the string representation of the specified object.	Object
		valueOf():Object Returns the primitive value of the specified object.	Object

Constructor Detail

Dictionary

()

Constructor

public function Dictionary(weakKeys:Boolean = false)

Language Version:

ActionScript 3.0

Runtime Versions:

AIR 1.0 Flash Player 9

Creates a new Dictionary object. To remove a key from a Dictionary object, use the delete operator.

Parameters

weakKeys:Boolean (default = false) — Instructs the Dictionary object to use "weak" references on object keys. If the only reference to an object is in the specified Dictionary object, the key is eligible for garbage collection and is removed from the table when the object is collected.