AS3 get random unique Characters from Alphabet array - arrays

Question

Feel free to copy and paste the code into your fla. It should work to trace vars.
I am trying to create a kids matching game. It selects one letter for the alphabet and will ask them to find that letter from 3 choices. I am also going to randomize the 3 letters they pick from but it is not yet in this code.
My issue is most of the time it is removing an array var using "POP" but sometimes and I get DUPLICATES and sometimes it comes out NULL. What am I doing wrong here?
import flash.events.MouseEvent;
import flash.display.*;
/// Array of the Alphabet
var Alphabet:Array = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"];
// Arry to hold 3 unique letters
var randArray:Array = new Array();
function getRandomElementOf(array:Array):Object
{
var idx:int=Math.floor(Math.random() * array.length);
// Supposed to remove the letter so can't be chosen again
array.pop()
// Adds 1 of 3 letters to new array
randArray.push(array[idx]);
return array[idx];
}
function testArray(evt:MouseEvent){
var One = getRandomElementOf(Alphabet);
trace(One);
var Two = getRandomElementOf(Alphabet);
trace(Two);
var Three = getRandomElementOf(Alphabet);
trace(Three);
trace("Can you find the letter " + One + "? " + randArray);
// Resets the random Array
randArray = new Array();
// Resets the letters forto be chosen again.
Alphabet = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"];
}
/// button to click stage to test vars
stage.addEventListener(MouseEvent.CLICK, testArray);

Answer 1

An example shuffler, splicing letters from the alphabet collection:
var alphabet:Vector.<String> = new <String>[ "A", "B", "C", "D", "E", "F", "G",
"H", "I", "J", "K", "L", "M", "N",
"O", "P", "Q", "R", "S", "T", "U",
"V", "W", "X", "Y", "Z" ];
while (alphabet.length > 0)
{
var letter:String = alphabet.splice(int(Math.random() *
alphabet.length), 1)[0];
trace(letter);
}
Example output:
V, M, F, E, D, U, S, L, X, K, Q, H, A, I, W, N, P, Y, J, C, T, O, R, G, B, Z
Applied to your example, here's a reset function to reset the alphabet collection back to its original state, a random letter function to remove a single letter from the alphabet collection, and a shuffle function to randomize the alphabet collection:
/** Alphabet collection */
var alphabet:Vector.<String>;
/** Reset alphabet */
function reset():void
{
alphabet = new <String>[ "A", "B", "C", "D", "E", "F", "G",
"H", "I", "J", "K", "L", "M", "N",
"O", "P", "Q", "R", "S", "T", "U",
"V", "W", "X", "Y", "Z" ];
}
/** Get random letter from alphabet */
function getRandomLetter():String
{
return (alphabet.splice(int(Math.random() *
alphabet.length), 1)[0]);
}
/** Shuffle alphabet collection */
function shuffleAlphabet():Vector.<String>
{
var alphabetShuffled:Vector.<String> = new Vector.<String>();
while (alphabet.length > 0)
{
alphabetShuffled.push(getRandomLetter());
}
return alphabetShuffled;
}
The following pulls a random letter from the alphabet to be found and display the entire alphabet shuffled:
// get a random letter:
reset();
var randomLetter:String = getRandomLetter();
trace("Can you find the letter: " + randomLetter + "?");
// display entire alpha shuffled:
reset();
trace(shuffleAlphabet());
Example game output:
Can you find the letter: Q?
R,I,U,J,Y,D,K,W,T,F,N,G,A,P,X,H,Q,L,S,O,C,V,M,Z,E,B
Can you find the letter: P?
I,F,C,S,J,P,Q,M,D,T,H,X,O,V,W,G,K,A,N,Y,L,U,Z,R,B,E
Can you find the letter: S?
B,U,O,S,C,N,I,E,W,L,P,Q,Z,R,A,G,J,K,Y,M,T,V,X,D,H,F

Answer 2

array.splice()
and not array.pop();
I figured it out.