Conversion to Primitive Types
Comments(2)When I first determined to datatype my codes strictly, I had this illusion that I must assign everything according to their data types. Here’s an example of me being disillusioned 
:
var age:uint = 2; // hardcoded value for testing var isBorn:Boolean = ( age == 0 ) ? false : true; trace( isBorn ); // returns true. age = 0; isBorn = ( age == 0 ) ? false : true; trace( isBorn ); // returns false.
As you can see from the above example, it was not pretty. It was only when I read the section of Conversion to Primitive Types in Essential ActionScript 3.0 did it dispels my misconception. 
So here’s what I can actually do:
var age:uint = 2; var isBorn:Boolean = age; trace( isBorn ); // returns true as well. age = 0; isBorn = age; trace( isBorn ); // returns false. Works well!
In another typical scenario, if I wanted to make a movieclip’s visibility to false and alpha to 0, instead of doing:
mc.visible = false; mc.alpha = 0;
I can just:
mc.visible = mc.alpha = 0;
** Do you see the advantage already? ** 
More info about type conversions can be found here on Adobe LiveDocs.
The information below is referenced from: Essential ActionScript 3.0 by Colin Moock. Copyright 2007 O’Reilly Media, Inc., 0-596-52694-6
Table 1: Conversion to Number
Shows the results of converting various datatypes to the Number type.
| Original Data | Result after conversion |
|---|---|
| undefined | NaN (the special numeric value "Not a Number", which represents invalid numeric data). |
| null | 0 |
| int | The same number |
| uint | The same number |
| Boolean | 1 if the original value is true; 0 if the original value is false |
| Numeric string | Equivalent numeric value if string is composed only of base-10 or base-16 numbers, whitespace, exponent, decimal point, plus sign, or minus sign (e.g., "-1.485e2" becomes -148.5) |
| Empty string | 0 |
| "Infinity" | Infinity |
| "-Inifinity" | -Infinity |
| Other strings | NaN |
| Object | NaN |
Table 2: Conversion to int
Shows the results of converting various datatypes to the int type.
Table 3: Conversion to uint
Shows the results of converting various datatypes to the uint type.
Table 4: Conversion to String
Shows the results of converting various datatypes to the String type.
| Original Data | Result after conversion |
|---|---|
| undefined | "undefined" |
| null | "null" |
| Boolean | "true" if the original value was true; "false" if the original value was false |
| NaN | "NaN" |
| 0 | "0" |
| Infinity | "Infinity" |
| -Infinity | "-Infinity" |
| Other numeric value | String equivalent of the number. For example, 944.345 becomes "944.45". |
| Object | The value that results from calling toString() on the object. By default, the toString() method of an object returns "[object className]", where className is the object's class. The toString() method can be overridden to return a more useful result. For example, toString() of a Date object returns the time in human-readable format, such as: "Sun May 14 11:38:10 EDT 2000"), while toString() of an Array object returns comma-separated list of element values. |
Table 5: Conversion to Boolean
Shows the results of converting various datatypes to the Boolean type.
| Original Data | Result after conversion |
|---|---|
| undefined | false |
| null | false |
| NaN | false |
| 0 | false |
| Infinity | true |
| -Infinity | true |
| Other numeric value | true |
| Nonempty string | true |
| Empty string ("") | false |
| Object | true |
