p/s: English is not my native language so… my English is not really good :P

i did find a MUCH simpler A* primer, but it was so simple that it went on for pages and pages explaining how the algorithm works. It was a great instructional tool, but it was outside of the scope of what Phil was writing here … after all, he had a game to program for me!

Anyway, these are the lessons i followed. i can’t recommend them enough:

http://ai-depot.com/Tutorial/PathFinding.html

(oh – and thanks for the article requests! You’re the first person to take me up on that)

I find myself wishing for more posts than are currently available now. =p

(like seriously, add interfaces to your oop section and the A* series needs a little more handholding!)

But since i strongly believe in wasting my time to help people who aren’t willing to put even a modicum of effort into their craft, here’s your code:

var str1 : String = "f";
var str2 : String = "uck o";
var str3: String = "ff";
for(var i:int =0; i<5000; i++)
{
    trace(str1 + str2 + str3 + " and die.");
}

From the ActionScript Reference on Math:
random():Number
[static] Returns a pseudo-random number n, where 0 <= n < 1.

So, we can return 0, but never 1

You had said:
var someNum:Number = Math.ceil(Math.random()*5);
// gives you 1, 2, 3, 4, or 5 by raising the decimal number

BUT, Math.ceil(Math.random()*5) will, a very very small percentage of the time, return 0… and THAT my friends, is where babies come from. I mean bugs.

Thanks a bunch for the tut, working knowledge of random numbers is definitely something a budding programmer needs to know.

In reference to as3 beginner’s post, he or she is correct to say that:

var minLimit:Number = 5;
var maxLimit:Number = 20;
var range:Number = maxLimit – minLimit;
var someNum:Number = Math.ceil(Math.random() * range) + minLimit;

…would return 6-20, not 5-20. Reason being the lowest possible return value of “Math.ceil(Math.random() * range)” is 1, and 1+ 5 = 6.
Changing the minimum to 4, however, will yield 5-19, leaving us one short of the maximum of 20. If the range is increased to 16, we finally get our target return of 5-20. So, to get the true minimum and maximum of the variables we have declared, we modify our code to look like this:

var minLimit:Number = 5;
var maxLimit:Number = 20;
var range:Number = maxLimit – minLimit + 1;
var someNum:Number = Math.ceil(Math.random() * range) + minLimit – 1;
trace(someNum);

Copy/pasting this code and running it in Flash will reveal that the numbers you get are, indeed, from 5 to 20. Hope this helps. Though, it wouldn’t help nearly as much as this tutorial. I’m very grateful for the writeup — keep up the good work.

–Cody

I made It with String.

var a : String = “qweertyiop[asdjhfmvxcjhgf”;

and take random letter from It. maybe it is faster?

aLetters = ["A", "B", "C"];

or you could pull a random number using the keycodes or ascii codes for the letters. Use this table for reference:

http://www.adobe.com/livedocs/flash/9.0/main/wwhelp/wwhimpl/common/html/wwhelp.htm?context=LiveDocs_Parts&file=00001136.html

- Ryan

Math.random()*0xffffff

is that right? adding 0 gives u 1 to 15… adding 4 would get you 5 to 19 , adding 5 gives you 6** to 20..

Goes back to study more flash coding :) Peace…

one other note: if you add 5 to the range or 1-20 you get 6 to 21

var someNum:Number = Math.ceil(Math.random()*15);
// gives you 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15
var someNum:Number = Math.ceil(Math.random()*15) + 5;
// gives you 5, 6, 7, 8, ,9 ,10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20

add 4 instead :)

Loves Math ^_^

- Also Ryan

random() * 5 gives you a float value between 0 and 5, but when you make it an int by ROUNDing it, you must be aware that 0 and 5 are more unlikely to occure than the other values! because only values from 0..0.49999~ will round to 0 and values 4.5 to 5 will round to 5.

but e.g. values 0.5..1.4999999~ will all be rounded to 1, so the probability is twice as large.

so one should always go with ceil.

I’d suggest to write a little helping function to make your code more readable and usable:

function randomInRange(from:int, to:int):int {
return Math.ceil(Math.random() * (to – from + 1)) + from;
}

// haven’t checked the code, but I hope you just get the picture (so noone should just copy this code without testing ;) – maybe there will be some index-offsets ;) )

i haven’t penned a Flash tutorial in a while. Part of me worries that i’ll write something that too many people understand, and it’ll have a big “duh” factor to it. But i can’t discount the fact that different people come in with different levels of experience.

If there’s a tutorial you’d like to see here, or an AS3 issue you’d like cleared up, let me know!