actionscript 3 - AS3 get random unique Characters from Alphabet array -

feel free copy , paste code fla. should work trace vars.

i trying create kids matching game. selects 1 letter alphabet , ask them find letter 3 choices. going randomize 3 letters pick not yet in code.

my issue of time removing array var using "pop" , duplicates , comes out null. doing wrong here?

import flash.events.mouseevent; import flash.display.*;  /// array of 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 hold 3 unique letters var randarray:array = new array();  function getrandomelementof(array:array):object  {     var idx:int=math.floor(math.random() * array.length);     // supposed remove letter can't chosen again     array.pop()      // adds 1 of 3 letters new array     randarray.push(array[idx]);     return array[idx]; }   function testarray(evt:mouseevent){   var 1 = getrandomelementof(alphabet); trace(one); var 2 = getrandomelementof(alphabet); trace(two); var 3 = getrandomelementof(alphabet); trace(three);  trace("can find letter " + 1 + "?   " + randarray);  // resets random array randarray = new array(); // resets letters forto 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 click stage test vars stage.addeventlistener(mouseevent.click, testarray); 

an example shuffler, splicing letters 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 example, here's reset function reset alphabet collection original state, random letter function remove single letter alphabet collection, , shuffle function randomize 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" ]; }  /** random letter 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 random letter alphabet found , display entire alphabet shuffled:

// random letter: reset(); var randomletter:string = getrandomletter();  trace("can find letter: " + randomletter + "?");  // display entire alpha shuffled: reset(); trace(shufflealphabet()); 

example game output:

can find 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 find 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 find 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