How to generate random number and use It few times? - actionscript-3

Question

So I need to generate random number and use It few times, problem is that It generating on EnterFrame function.
This function generate number 0-5:
function pn():Number {
var pn:Number = Math.round(Math.random()*5);
return pn;
}
Here I check if character not jumping and stage.addEventListener(Event.ENTER_FRAME, jump);
if(!mainJumping){
mainJumping = true;
stage.addEventListener(Event.ENTER_FRAME, jump)
}
And here is jump function where I need to use random generated number:
function jump(e) {
if ( i < 50) {
i++;
item[1][pn()].y -=1
} else {
item[1][pn()].y += 1;
if (item[1][pn()].y == 0){
stage.removeEventListener(Event.ENTER_FRAME, jump)
}
}
Problem is that in jump function every time IF is checked It generates new number. I need to make that number will be generated and not changed till this part:
if (item[1][pn()].y == 0){
stage.removeEventListener(Event.ENTER_FRAME, jump)
}
After this It can generate new number. Have you ideas? Thank you.

Answer 1

// Create a variable higher up the scope chain to store the number
var random = 0;
// Assuming this is in a function at the same level as the jump function
//function() ???? {
if(!mainJumping){
mainJumping = true;
random = pn(); // Generate new random number when jump begins
stage.addEventListener(Event.ENTER_FRAME, jump)
}
//}
function jump(e) {
var item = item[1][random]; // Grab the random item
if ( i < 50) {
i++;
item.y -=1
} else {
item.y += 1;
if (item.y == 0){
stage.removeEventListener(Event.ENTER_FRAME, jump)
}
}
}

Answer 2

Create an instance variable called myRandomNumber. In the getter for it, if it is null, call pn() to populate it.
Something like this:
In your class, define the variable:
private var _myRandomNumber:int = 0;
And in your getter:
public function get myRandomNumber():int {
if (_myRandomNumber == 0) {
_myRandomNumber = pn();
}
return _myRandomNumber;
}
Now, when you call myRandomNumber, you'll get a "random number" :)