Tutorials Home What's New Top Rated Submit myTutes Random!

Flash Actionscript Programming Basics
Author: Steve Happ | Website: http://www.video-animation.com |

Page 2
«prev 1 2 3 4 5 next»

Comments

Comments are helpful lines that are not compiled.

• They help readers understand our program,
• summarize a function's algorithm,
• identify the purpose of a variable, or
• clarify a segment of code.

There are two types.

1. Multiple Lines ( /* */ )
   

   /*
   An explanation of a section of code or
    a coder's name and date
   and other stuff
   */
   

2. Single Line delimiters (//)
   

   // number of record
   var recordNum ;
   

Operators

Operators are signs that do something to variables on either side of them. Here are the arithmetic operators:

Operator	Name	Example
*	Multiplication	X* Y
/	Division	X/Y
%	Modulus	X % Y
+	Addition	X + Y
-	Subtraction	X - Y

The Modulus operator(%) computes the remainder of division between 2 integers.
e.g. 5 % 2 = 1
5/2 = (2*2) + 1(remainder)
Try it out! Ex1.

 var x = 3;
 var y = 5;
 var mult1 =  x * y;
 trace(x + " times " + y + " = " + mult1);

ex2

var min = 35;
var max = 239;
var addition = min + max;
trace(min + " plus " + max + " = " + addition;

You get the idea. Try all the operators and start writing your own scripts.

Equality, Relational and Logical Operators

These operators evaluate to true or false

Logical AND (&&)

Evaluates to true only if both its operands evaluate to true. E.g.

 x = 5;
 if(x>0 && x <10){
something = true;
}
trace(something);

BOTH MUST BE TRUE.

Logical OR ( || )

Evaluates to true if either of its operands evaluate to true. E.g.

 x = 5;
If(x>0 || x<4){
something = true;
}
trace(something);

EITHER CAN BE TRUE

Operator	Name	Example
!	Logical NOT	(!hasFired)
<	Less than	x
>	Greater than	x> y
<=	Less than or equal to	x <= y
>=	Greater than or equal to	x>= 24
==	Equality	if(hasFired == true)
!=	Inequality	If( x != 7)
&&	Logical AND	x>0 && x <10
||	Logical OR	x<0 || x> 20

Assignment Operator ( = )

The effect that an assignment has is to store a new value in the left operand's associated memory storage space e.g.

 x = 7;

This statement means that the value 7 is assigned to the variable x.

Increment and decrement Operators ( ++ and -- )

The increment (++) and decrement (--) operators are a shortcut way of adding or subtracting 1 from a variable. E.g.
Prefix increment - ++c; // c = c+1
Postfix increment - c++;
The prefix form of ++ increments the value of the variable before that value is used.

stack[++top] = val;
//Is equivalent to the following 2 lines
top = top +1;
stack[top] = val;

The postfix form of ( --) decrements the value of top after that value is used.

stack[top--] = val;
//Is equivalent to :
 stack[top] = v;
 top = top -1;

«prev 1 2 3 4 5 next»

» Level Basic

Added: : 2005-08-10 Rating: 8.17 Votes: 12 Hits: 674

» Author

Steve Happ is the founder of Steve's Tutes and has been going hard at it developing Flash for Web and CD-rom.

» Download

Download the files used in this tutorial.

Download (0 kb)

Get conversion and unzipping tools for PC and Mac here!

» Forums
	More help? Search our boards for quick answers!

Please rate this tutorial, 10 is the top rating, you can also click the comments link to read/write a review.

10 9 8 7 6 5 4 3 2 1