Question

I have a spot a difference game that every time I solve an image, and I click next it will load another MC from library.

Below is my code to randomly loaded the MC from library:

var showMcNum:Number = 0;
var movieList:Array = [mc1,mc2,mc3];
function getRandomMovie():MovieClip
{
    return new movieList[Math.floor(Math.random()*movieList.length)];
}
nextBtn.addEventListener(MouseEvent.CLICK, nextClick);
function nextClick(event:MouseEvent):void
{
    var mc:MovieClip = getRandomMovie();
    addChild(mc);
    mc.x = stage.stageWidth / 2;
    mc.y = stage.stageHeight / 2;
}

I would like to every time I click the next button, then it will load another MC from library without repeatation of those MC.

Answer 1

If you don’t want an MC to repeat, just remove it from the list when you return it.

function getRandomMovie():MovieClip
{
    var index:int = Math.floor(Math.random()*movieList.length);
    var mcClass:Class = movieList.splice(index,1)[0];
    return new mcClass();
}

Here is a version using a second array to allow you to repeat the list as per TheSHEEEP’s comment:

function getRandomMovie():MovieClip
{
    if(!movieList.length) {
        movieList = spareList;
        spareList = [];
    }
    var index:int = Math.floor(Math.random()*movieList.length);
    var mcClass:Class = movieList.splice(index,1)[0];
    spareList.push(mcClass);
    return new mcClass();
}

Removing the previous MovieClip

In order to remove the previous MovieClip, you should keep a record of it outside of your nextClick function, so that you can remove it before getting the next one:

//declare mc outside
var mc:MovieClip;
function nextClick(event:MouseEvent):void
{
    //remove mc first
    if(mc && mc.parent) removeChild(mc);
    //(optional) free up old mc for garbage collection
    //now replace the contents of mc with a new random instance
    mc = getRandomMovie();
    addChild(mc);
    mc.x = stage.stageWidth / 2;
    mc.y = stage.stageHeight / 2;
}

Of course you may need to do more than just remove the previous mc. Before you point your mc reference at a new object, you should free the other one up for garbage collection by stopping any internal code from executing and removing any listeners.