Looping and Removing Children stored in Array - arrays

I have an Array that holds a few MCs... There is a reset in my app that clears the array and removes the MCs from the stage. It works fine if I test one at a time like this:
if (myArray.length > 0)
{
removeChild(myArray[0]);
}
However if I try to iterate through the Array somehow as to remove all the objects (pr even just one in this case) it doesn't seem to know what the parent object is and therefore can't remove it. I've tried explicitly tell it myArray[0].parent.(removeChild(...) but It throws the same error. Currently I'm trying this:
while (myArray.length > 0)
{
removeChild(myArray[0]); // this line 'must be a child of the caller'
}
Other kinds of loops return the same error. If I trace the objects parent it prints the correct object too... So I'm at a loss. Am I missing something obvious or is there a better way to do this?

Your code will always try to remove the first element in myArray. So first time you could remove the element, and the element isn't the child of his parent anymore.When in the second time, you are trying to remove the first element again and as the element has no parent(it was removed last time), it will give you an error.
So you should remove each element in the array, not same element.
Try this
while (myArray.length > 0)
{
var mc = myArray.shift();
removeChild(mc);
}
If you don't want to remove element in myArray, you can use a count to save if you have remove all elements.Or just use for each like you did.
var count:int = 0;
while (count < myArray.length)
{
var mc = myArray[count];
removeChild(mc);
count++;
}

Related

how to add an object to array immediately after set to empty "[ ]" Vue

I need after call a function, set to empty an array and immediately add a new one to there.
This is becouse when an #click event is called i need to call a dialog and populate the content of this with a dynamic component (called them with a slug propertie), so the array should be change accordily to pass the slug propertie to the component.
My code is:
slugs: []
slugConversacion(slug) {
if (this.slugs > 0) {
this.slugs = []
// this.slugs.splice(this.slugs.indexOf(slug), 0);
// this.$delete(this.slugs, this.slugs.indexOf(slug))
}
else {
this.slugs.push(slug);
}
}
<Conversacion
v-for="slug in slugs"
:key="slug.id"
:slug="slug.slug"
></Conversacion>
This not work because when i click the event slugConversacion() set and empty array and only when clicked again, populate. I think that is for the if/else conditional.
What would be the right approach ? Thanks!
Just do this:
if (this.slugs.length > 0) {
this.slugs = [];
}
this.slugs.push(slug);
If you have trouble with setting array to empty with assigning [] to array and loosing reactivity, then you can try next thing.
This works for me as the last resort:
var i = slugs.length;
while(i --){
slugs.splice(i, 1);
}
You should do splice in revers mode because of index confusion: every time will be remained array element with index 1 if you will go throw the loop via
slugs.forEach((item, index) => {
slugs.splice(index, 1);
});
And after that you can do:
this.slugs.push(slug);

Error while using removeChild() and accessing members of array

I am stuck doing this even though I know it's very simple. Yet, I am getting errors.
What I have:
I have 3 arrays.
1st Array contains objects of UpgradeButton class.
2nd Array contains objects of BuyButtonclass.
3rd Array named newCostlyShops contains Numbers.
BuyButton class and UpgradeButton class, both have a shopCode member which is a number; the number which I'm trying to equate.
What I'm trying to do:
My goal is to first look for BuyButton and UpgradeButton objects in the respective arrays which have shopCodes same as those in newCostlyShops.
After that, I removeChild() that object and splice it out from the array.
My Code:
Array 3:
var newCostlyShops:Array = new Array();
newCostlyShops = Object(root).WorkScreen_mc.returnCostlyShops();
trace(newCostlyShops); // this is tracing out the exact shopCodes I want and is working fine.
Deletion and Splicing codes:
for (looper = 0; looper < upgradeButtonsArray.length; looper++) {
for (var secondLooper: int = 0; secondLooper < newCostlyShops.length; secondLooper++) {
if (upgradeButtonsArray[looper].shopCode == newCostlyShops[secondLooper]) {
trace(looper);
trace(upgradeButtonsArray[looper]);
removeChild(upgradeButtonsArray[looper]);
upgradeButtonsArray.splice(looper, 1);
}
}
}
for (looper = 0; looper < buyButtonsArray.length; looper++) {
for (secondLooper = 0; secondLooper < newCostlyShops.length; secondLooper++) {
if (buyButtonsArray[looper].shopCode == newCostlyShops[secondLooper]) {
trace(looper);
trace(buyButtonsArray[looper]);
removeChild(buyButtonsArray[looper]);
buyButtonsArray.splice(looper, 1);
}
}
}
What's wrong with this Code:
I keep getting error
TypeError: Error #1010: A term is undefined and has no properties.
This error comes only after the 1st time this code is run and not the first time it is run. When I remove the removeChild and splice , this traces out objects that are not null, ever. Even after this whole function is called 100 times, the error is not shown. Only when I removeChild and use splice this occurs.
Is there something wrong with what I'm doing? How to avoid this error? This is throwing the whole program haywire. If there is any other alternative to this method, I'm open to take those methods as well as long as I don't get errors and my goal is reached.
It might sounds funny, but.... try to decrement looper after splicing.
trace(looper);
trace(upgradeButtonsArray[looper]);
removeChild(upgradeButtonsArray[looper]);
upgradeButtonsArray.splice(looper, 1);
looper--;
I think after splicing the array all item's are being shifted and you're skipping next one.
Also, you should get some more information with this error, like which class/line is throwing it. Maybe you need to enable "permit debugging" or something?
Bonus suggestion:
For newCostlyShops use Dictionary instead of Array so you won't have to nest for inside for...

as3 array of objects - movement with constant speed

Ok, so I have some experience with as3 and some of the basics. But this problem has been stumping me for so long. I tried to do a workaround based on what I currently know about as3. But somehow either i get an error message or it just doesn't do anything at all. Here is the code that i'm trying to solve.
var zombieCount:Array = new Array();
var helltime:Timer = new Timer(1500);
helltime.addEventListener(TimerEvent.TIMER, spawnzombies)
helltime.start();
function spawnzombies(happened:TimerEvent){
var zombie1:Zombie = new Zombie();
zombieCount.push(zombie1);
stage.addChild(zombieCount[zombieCount.length - 1]);
zombie1.x = 135 + (330*Math.random())
zombie1.y = -29
stage.addEventListener(Event.ENTER_FRAME, move_zombie)
function move_zombie(happened:Event){
for(var i:int; i < zombieCount.length; i++){
zombieCount[i].y = zombieCount[i].y + 1;
if(zombieCount[i].hitTestObject(border)){
stage.removeChild(zombieCount[i]);
zombieCount.shift();
trace(zombieCount.length);
}
}
}
}
While this may not be inclusive of everything wrong, here are at least a few of the issues I see.
Inline function issue:
Inside your timer tick handler (spawnZombies), you create an inline function called move_zombie and then add an enter frame handler that calls that function.
The issue here, is that every tick of the timer, will then create a whole new copy of that function, and add ANOTHER enter frame handler. This will create huge problems after a few timer ticks.
Break that move_zombie function OUT OF the spawn function:
eg:
helltime.addEventListener(TimerEvent.TIMER, spawnzombies)
helltime.start();
stage.addEventListener(Event.ENTER_FRAME, move_zombie);
function move_zombie(......
function spawnzombies(.....
Iteration issue:
In your for loop:
for(var i:int; i < zombieCount.length; i++){
zombieCount[i].y = zombieCount[i].y + 1;
if(zombieCount[i].hitTestObject(border)){
stage.removeChild(zombieCount[i]);
zombieCount.shift();
trace(zombieCount.length);
}
}
You are not initializing your i value. While this will default it to 0, it's still a good idea for readability to initialize it.
So your iterating forward from 0 to the end of the array. However, if your hit test succeeds, you then use the shift method of the array. This removes the first item of the array (irrespective of what value i is at the time). This will remove the wrong item, plus mess up what zombieCount[i] refers to (because the amount of items has now changed after doing shift, so the next iteration zombieCount[i] will be a reference to same item as the previous iteration).
Instead of what you're currently doing, use the splice method to remove, and iterate backwards so your index doesn't get out of whack.
for(var i:int=zombieCount.length-1;i >=0;i--){
zombieCount[i].y += 1; //move it down 1 pixel
if(zombieCount[i].hitTestObject(border)){
stage.removeChild(zombieCount[i]);
zombieCount.splice(i,1); //remove the item at the current index (do this instead of shift)
trace(zombieCount.length);
}
}

Listener for every array element

i've created an array. Each element is a button object. Is there a possibility to hook mouseclick on every array at the same time? I mean something like this.
var Objects:Array = new Array
Objects[0] = new button(parameters)
Objects[1] = new button(parameters)
Objects[2] = new button(parameters)
Objects[n].addEventListener(MouseEvent.CLICK, Clicked(n));
function Clicked(n,...)
{
THECODE PROCEEEEDS for Objects[n]
}
I know that's not the clearest and most correct writing, but I'm asking if this is possible in similiar way? And how to do it? I know I can hook every mouseclick and then check if the clicked under the mouse is one of the array elements with for loop, but I'm asking about this way.
Yes. You are unable to directly pass an index into a listener, but you can retrieve that via calling indexOf() inside it.
for each (b in Objects) b.addEventListener(MouseEvent.CLICK, clicked);
// note, you just put function name here!
public function clicked(e:MouseEent):void {
var i:int=Object.indexOf(e.target);
if (i==-1) {
// panic behavior
return;
}
// now you can parse that index into something valuable
}

How would I remove a "row" in an array depending on the value of an element?

Here's what I'm currently doing/trying to do to accomplish my goal. But it is not removing the "row" the way I would like it too.
So, I'm making an object, then pushing it into an array. And the adding to the array part works fine and just as I expect.
var nearProfileInfoObj:Object = new Object();
nearProfileInfoObj.type = "userInfo";
nearProfileInfoObj.dowhat = "add";
nearProfileInfoObj.userid = netConnection.nearID;
nearProfileInfoObj.username = username_input_txt.text;
nearProfileInfoObj.sex = sex_input_txt.selectedItem.toString();
nearProfileInfoObj.age = age_input_txt.selectedItem;
nearProfileInfoObj.location = location_input_txt.text;
nearProfileInfoObj.headline = headline_input_txt.text;
theArray.push(nearProfileInfoObj);
So after that later on I need to be able to remove that object from the array, and it's not working the way I'm expecting. I want to take a variable whoLeft and capture their ID and then look in the array for that particular ID in the userid part of the object and if its there DELETE that whole "row".
I know you can do a filter with an array collection but that doesnt actually delete it. I need to delete it because I may be adding the same value again later on.
whoLeft = theiruserIDVariable;
theArray.filter(userLeaving);
public function userLeaving(element:*, index:int, arr:Array):Boolean
{
if (element.userid == whoLeft)
{
return false;
}
else
{
return true;
}
}
But this doesnt seem to be deleting the whole row like it implies. Does anyone know what i'm doing wrong?
Instead of modifying the original array, the new filtered array is returned by the filter method. So you need to assign the returned array to theArray.
Try this
theArray = theArray.filter(userLeaving);
EDIT This turned out to be slower than for loop:
An alternative to the hand coded loop could be something like this:
theArray.every(searchAndDestroy);
public function searchAndDestroy(element:*, index:int, arr:Array):Boolean
{
if (element.userid == whoLeft)
{
arr.splice(index,1);
return false;
}
return true;
}
As far as I know, every() terminates the first time the test function returns false. So the question is: for a big list, which is faster, the for loop or the loop that every() does with the overhead of the test function call.
EDIT #2 But this was faster than a for loop for a test I ran on an array of a million Points:
for each(var element:Object in theArray)
{
if (element.userid==whoLeft)
{
theArray.splice(theArray.indexOf(element),1);
break;
}
}
I think this is what you're looking for:
for(var i:uint = 0, len:uint = theArray.length; i<len; i++)
{
if(thisArray[i].id == whoLeft.id)
{
thisArray.splice(i, 1);
break;
}
}
However, do you really need it in an Array because you could always use a Dictionary which would mean accessing it by id which would be a lot simpler to remove.

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