Difference between revisions of "Actionscript"

Latest revision as of 03:39, 1 June 2009

http://ntt.cc/2008/04/09/over-30-useful-as3-open-source-projects.html

Basics

Operators

• + for addition
• - for subtraction
• asterisk for multiply
• / for divide

these two are the same:

myNum = myNum + 6;
myNum += 6;

• ++ add one
• -- decrease by one

those can be postfix or prefix operators but remember that only prefix affects it immediately.

myNum = 5;
trace(myNum++);       // displays 5 (adds one to next trace)
trace(myNum);       // displays 6 (has added one from the postfix)
trace(++myNum);       // displays 7 (adds one as its a prefix)

use this incremental thing to modify property over time:

my_mc.onEnterFrame = function () {
this._rotation += 5;       // makes mc rotate by 5 degrees clockwise for each tick of frame rate
};

Checking/Comparing Values

• == checks for logical equality
•  != checks for logical inequality
• === checks for strict logical equality
•  !== checks for strict logical inequality

logical equality test 
trace(5 == 6);       // false               
trace(6 == 6);       // true
trace(6 == "6");       // true

logical inequality test
trace(5 != 6);       // true               
trace(6 != 6);       // false               
trace(6 != "6");       // false

notice how with or without the quotation marks its okay... but with the strict logical operators, its not the case.

strict logical equality test 
trace(5 === 6);       // false               
trace(6 === 6);       // true
trace(6 === "6");       // false
trace("6" === 6);       // false
trace("6" === "6");       // true

strict logical inequality test
trace(5 !== 6);       // true               
trace(6 !== 6);       // false               
trace(6 !== "6");       // true
trace("6" !== 6);       // true
trace("6" !== "6");       // false

you have to remember that you shouldn't use just one = to test if its equal as the single = assigns values to things.

Checking Datatype

var myVar = 5;
if (typeof myVar == "number") {
  trace("Its a number");
}

NaN is when its Not a Number but you can't just check it against the NaN. You have to use the special isNaN function (conversely, you can also use !isNaN to find a number)

var myVar - 15 - "coffee";
if (isNaN(myVar)) {
trace("Thats not a number");
}

Comparing Arrays

when arrays are compared to see if they are the same, it has to be the exact same thing ie: can't just contain the same items, it has to be equalled, like literally...

arrayOne = newArray("wonk", "wink");
arrayTwo = newArray("wonk", "wink");
trace(arrayOne == arrayTwo);		// displays false

arrayOne = newArray("wonk", "wink");
arrayOne = arrayTwo;
trace(arrayOne == arrayTwo);		// displays true

Conditionals

var message = "yellow";                         // the equal sign assigns values to variables
trace ("big " + message + " truck");            // prints "big yellow truck"
if (message == "yellow") {                      // the double equal sign checks to see if variables are equal
trace ("yes, i did say big yellow truck.");     // prints "yes, i did say big yellow truck"
trace (typeof message);                         // prints "string"
var x = a;                                      // prints "number"
trace (typeof a)
}

var x = 1;
while (x <= 5) {                // as long as x is less than 5...
trace (x);                      // return 1 in output
x = x + 1;                      // return 2 3 4 5 in output
}

Reusable functions

Runtime Environment

Include external actionscript file

#include "filename.as"          // includes the .as file at runtime (must be in same folder as .fla)

Detecting player/OS

Setting movie dimensions

Color

Setting RGB

Setting Transparency

Transform and restore RGB

Controlling RGB with sliders

Drawing

Numbers

Rounding Numbers

Text Field

Arrays

Oh no.

Strings

Date/Time

See Also