Button generating a cross sum - function

Question

I'm looking for a tip for a AS3 script, have no idea how to start there
Button, if clicked the function is executed, which outputs a predefined value as the cross sum of a number string.
Example:
Cross sum should be 10
By clicking on the button, the function generates the number 55 or 82 or 37 or 523, ie numbers with the cross sum 10

Answer 1

An alternative way using % (modulo) instead of a string. You could write that into one line like this:
while (sum != 0) { qsum += sum % 10; sum /= 10; }
The trick is that modulo will give us only the last digit of the longer number, then we divide by 10 to trim off that last number (from longer) and we re-read a newer ending digit of the long number.
Example:
Long num = 1234, so each trim gives, 4 then 3 then 2 then 1 and we'll sum them up each time.
usage:
myInt = cross_sum(50); //makes myInt hold answer result of function (where ExpectedValue input is 50).
and the supporting function...
function cross_sum( ExpectedValue: int ) : int
{
var rand :int = Math.floor(Math.random() * 100000000000)
var sum :int = Math.abs( rand );
var qsum :int = 0;
while (sum != 0)
{
qsum += sum % 10; //get last digit of sum...
sum /= 10; //trim down sum by 1 digit...
}
if ( qsum == ExpectedValue ) { return rand; } //# stop here and give back "rand" as answer result.
else { cross_sum( expectedValue ); } //# else if wrong, try again...
}

Answer 2

Got it now.....
the function calculates a number, with the crosssum 50
function berechnen() {
var rand = Math.floor(Math.random() * 100000000000)
var sum = String(rand)
var qsum = 0;
for (var i = 0; i < sum.length; i++) {
qsum += Number(sum.charAt(i));
}
if (qsum == 50) {
summe.text = String(sum);
} else {
berechnen()
}
}