Edison’s Blog

“Type(var)” vs “var as Type”

April 23rd, 2010

Description:
I have done an experiment to test the performance of data type conversions in actionscript 3. Create a new flex 4 based application with the code below, then compile and run it:

CODE:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
			   xmlns:s="library://ns.adobe.com/flex/spark"
			   xmlns:mx="library://ns.adobe.com/flex/mx"
			   minWidth="955" minHeight="600"
			   xmlns:controls="com.wds.framework.controls.*"
			   initialize="application1_initializeHandler(event)">
	<fx:Script>
		<![CDATA[
			import mx.containers.Canvas;
			import mx.core.Container;
			import mx.core.FlexSprite;
			import mx.core.IContainer;
			import mx.core.IUIComponent;
			import mx.core.UIComponent;
			import mx.events.FlexEvent;
			import mx.utils.ObjectProxy;
 
			protected function application1_initializeHandler(event:FlexEvent):void
			{
				var n:int = 1000000;
				var i:int = 0;
				var timer:int = 0;
				var obj:*;
 
				trace("--------------------------");
				////////////////////////////////////////////////////
				trace("Basic Types");
				trace("-----------");
				obj = {};
				trace("obj = {}");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					Object(obj);
				}
				trace("Object(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as Object;
				}
				trace("obj as Object",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = "str";
				trace("obj = \"str\"");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					String(obj);
				}
				trace("String(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as String;
				}
				trace("obj as String",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = 0.5;
				trace("obj = 0.5");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					Number(obj);
				}
				trace("Number(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as Number;
				}
				trace("obj as Number",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = -12;
				trace("obj = -12");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					int(obj);
				}
				trace("int(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as int;
				}
				trace("obj as int",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = 12;
				trace("obj = 12");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					uint(obj);
				}
				trace("uint(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as uint;
				}
				trace("obj as uint",getTimer() - timer);
				trace("-----------");
 
				////////////////////////////////////////////////////
				trace("Dynamic Classes");
				trace("-----------");
				obj = new Array();
				trace("obj = new Array()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					Array(obj);
				}
				trace("Array(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as Array;
				}
				trace("obj as Array",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new ObjectProxy();
				trace("obj = new ObjectProxy()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					ObjectProxy(obj);
				}
				trace("ObjectProxy(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as ObjectProxy;
				}
				trace("obj as ObjectProxy",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new MyDynamicClass();
				trace("obj = new MyDynamicClass()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					MyDynamicClass(obj);
				}
				trace("MyDynamicClass(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as MyDynamicClass;
				}
				trace("obj as MyDynamicClass",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new MyProxyClass();
				trace("obj = new MyProxyClass()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					MyProxyClass(obj);
				}
				trace("MyProxyClass(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as MyProxyClass;
				}
				trace("obj as MyProxyClass",getTimer() - timer);
				trace("-----------");
				////////////////////////////////////////////////////
				trace("Typed Classes");
				trace("-----------");
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					Canvas(obj);
				}
				trace("Canvas(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as Canvas;
				}
				trace("obj as Canvas",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					Container(obj);
				}
				trace("Container(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as Container;
				}
				trace("obj as Container",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					UIComponent(obj);
				}
				trace("UIComponent(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as UIComponent;
				}
				trace("obj as UIComponent",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					Sprite(obj);
				}
				trace("Sprite(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as Sprite;
				}
				trace("obj as Sprite",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					DisplayObject(obj);
				}
				trace("DisplayObject(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as DisplayObject;
				}
				trace("obj as DisplayObject",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					EventDispatcher(obj);
				}
				trace("EventDispatcher(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as EventDispatcher;
				}
				trace("obj as EventDispatcher",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					Object(obj);
				}
				trace("Object(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as Object;
				}
				trace("obj as Object",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Container();
				trace("obj = new Container()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					Container(obj);
				}
				trace("Container(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as Container;
				}
				trace("obj as Container",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new UIComponent();
				trace("obj = new UIComponent()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					UIComponent(obj);
				}
				trace("UIComponent(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as UIComponent;
				}
				trace("obj as UIComponent",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new FlexSprite();
				trace("obj = new FlexSprite()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					FlexSprite(obj);
				}
				trace("FlexSprite(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as FlexSprite;
				}
				trace("obj as FlexSprite",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Sprite();
				trace("obj = new Sprite()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					Sprite(obj);
				}
				trace("Sprite(obj)",getTimer() - timer);
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as Sprite;
				}
				trace("obj as Sprite",getTimer() - timer);
				trace("-----------");
 
				////////////////////////////////////////////////////
				trace("Interfaces");
				trace("-----------");
				//////////////////////////
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					IContainer(obj);
				}
				trace("IContainer(obj)",getTimer() - timer);				
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as IContainer;
				}
				trace("obj as IContainer",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					IUIComponent(obj);
				}
				trace("IUIComponent(obj)",getTimer() - timer);				
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as IUIComponent;
				}
				trace("obj as IUIComponent",getTimer() - timer);
				trace();
 
				//////////////////////////
				obj = new Canvas();
				trace("obj = new Canvas()");
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					IEventDispatcher(obj);
				}
				trace("IEventDispatcher(obj)",getTimer() - timer);				
 
				timer = getTimer();
				for(i = 0;i < n;i++)
				{
					obj as IEventDispatcher;
				}
				trace("obj as IEventDispatcher",getTimer() - timer);
				trace();
			}
 
		]]>
	</fx:Script>
</s:Application>

RESULTS:

--------------------------
Basic Types
-----------
obj = {}
Object(obj) 150
obj as Object 109

obj = "str"
String(obj) 110
obj as String 110

obj = 0.5
Number(obj) 65
obj as Number 107

obj = -12
int(obj) 67
obj as int 110

obj = 12
uint(obj) 67
obj as uint 108
-----------
Dynamic Classes
-----------
obj = new Array()
Array(obj) 1563
obj as Array 113

obj = new ObjectProxy()
ObjectProxy(obj) 126
obj as ObjectProxy 134

obj = new MyDynamicClass()
MyDynamicClass(obj) 128
obj as MyDynamicClass 138

obj = new MyProxyClass()
MyProxyClass(obj) 133
obj as MyProxyClass 135
-----------
Typed Classes
-----------
obj = new Canvas()
Canvas(obj) 131
obj as Canvas 132

obj = new Canvas()
Container(obj) 136
obj as Container 144

obj = new Canvas()
UIComponent(obj) 141
obj as UIComponent 148

obj = new Canvas()
Sprite(obj) 176
obj as Sprite 124

obj = new Canvas()
DisplayObject(obj) 167
obj as DisplayObject 122

obj = new Canvas()
EventDispatcher(obj) 170
obj as EventDispatcher 125

obj = new Canvas()
Object(obj) 150
obj as Object 108

obj = new Container()
Container(obj) 132
obj as Container 138

obj = new UIComponent()
UIComponent(obj) 134
obj as UIComponent 138

obj = new FlexSprite()
FlexSprite(obj) 133
obj as FlexSprite 134

obj = new Sprite()
Sprite(obj) 170
obj as Sprite 120
-----------
Interfaces
-----------
obj = new Canvas()
IContainer(obj) 136
obj as IContainer 147

obj = new Canvas()
IUIComponent(obj) 139
obj as IUIComponent 148

obj = new Canvas()
IEventDispatcher(obj) 120
obj as IEventDispatcher 121

Conclusion

To convert an Object instance to String, uint, int or Number, “Type(var)” is faster than “var as Type”
To convert an Object instance to Array, ”Type(var)” is much slower than “var as Type”, you can receive a warning “Array(x) behaves the same as new Array(x). To cast a value to type Array use the expression x as Array instead of Array(x)” with Flash Builder 4.
To convert an Object instance of a sub-class to its super class, “var as Type” is faster than “Type(var)” if the super class is not Sprite or its super classes.
To convert an Object instance of a class to that class instance, ”var as Type” is faster than “Type(var)” sometimes if the super class is not Sprite or its super classes.
To convert an Object instance of a class as an interface, ”Type(var)” is faster than “var as Type”.

This entry was posted on Friday, April 23rd, 2010 at 11:15 pm and is filed under Actionscript.

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