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.
Related
I created this service method in Angular JS which checks if an array of potential statuses(pendingApplications) match any of an array of set statuses(applicableStatuses). For this to work it meetsStatusCondition should return true after the first match occurs. Only 1 of the numbers in pendingApplications array needs to match and I'd like to end the execution of this function. Currently it's looping through every item in pendingApplications array
`containsApplicableStatus: function(pendingApplications, applicableStatuses) {
pendingApplications.forEach(function(status) {
if (applicableStatuses.includes(status)) {
return pendingApplications.meetsStatusCondition = true;
}
});
}`
This is a limitation with .forEach, you can't break out if it like you can with a for loop
Just a regular for loop will work
for (const status of applicableStatuses){
if (applicableStatuses.includes(status)) {
pendingApplications.meetsStatusCondition = true;
break //or return if you want to exit out of the enclosing function instead of just the loop
}
}
Often when you want to short-circuit a forEach like this, what you're really looking for is another method like find() or some().
containsApplicableStatus: function(pendingApplications, applicableStatuses) {
pendingApplications.meetsStatusCondition = pendingApplications.some(function(status) {
return applicableStatuses.includes(status)
});
}
There is no point in using forEach (which doesn't have a breaking option) if you could just use a regular for ... of loop instead:
containsApplicableStatus: function(pendingApplications, applicableStatuses) {
for (const status of pendingApplications) {
if (applicableStatuses.includes(status)) {
pendingApplications.meetsStatusCondition = true;
break;
}
}
}
However, even this seems a bit too complicated, you could just set meetsStatusCondition to the result of some:
containsApplicableStatus: function(pendingApplications, applicableStatuses) {
pendingApplications.meetsStatusCondition =
pendingApplications.some(status => applicableStatues.includes(status));
}
I do wonder if it makes sense to set a non-index property on your array though, maybe rethink that. This works but it's usually not something you'd expect on an array, and it will be lost if you convert that array to JSON for instance.
I have a computed array which is full of tags and updates depending on what selection i make in the select box. I would like to take this array and pass it to a method and then run a method to update what “results” have an active class. Although I get an array saying I can’t run forEach on this element.
Been through a few topics and understand computed properties dont work like that but surely there is a way around this.
https://jsfiddle.net/39jb3fzw/6/
Short Snippet
methods: {
updateOutput() {
var tags = this.tagArray;
tags.forEach(function(tag) {
console.log(tag);
})
}
},
computed: {
concatenated: function () {
var ret = this.selected.concat(this.selected2, this.selected3);
this.tagArray = ret;
//this.updateOutput();
return ret;
}
}
Full Output
https://jsfiddle.net/39jb3fzw/6/
Thanks again :slight_smile:
It looks like the issue is the line:
var ret = this.selected.concat(this.selected2, this.selected3);
That line of code is returning an empty string rather than an array. This is because this.selectedX is a string rather than an Array. This explains why tag.forEach is undefined. forEach doesn't exist on the String prototype.
You can create this an array instead be doing
var ret = [ this.selected, this.selected2, this.selected3 ]
From there you can set this.tagArray to ret
Hope this helps
I have a store and an array. I want to remove records from the store if that record's value matches with values in the array. Following is is the code I am trying but it's not working. Can anyone suggest the correct way?
'store' is the actual store and 'filterItems' is the array of records I want to remove from 'store'.
store.each(function (record) {
for (var i = 0; i < filterItems.length; i++) {
if (record.get('ItemId') === _filterItems[i].get('ItemId')) {
itemIndex = store.data.indexOf(record);
store.removeAt(itemIndex );
}
}
});
Not sure about your code because i dont know all variables. Though its recommended to use the store.getRange() fn and iterate the array via for loop. Its better for performance.
var storeItems = store.getRange(),
i = 0;
for(; i<storeItems.length; i++){
if(Ext.Array.contains(filterItemIds, storeItems[i].get('id')))
store.remove(store.getById(storeItems[i].get('id')));
}
Here is an example which i tried right now and it works well.
https://fiddle.sencha.com/#fiddle/8r2
Try using the remove method of the store (docs)
store.remove(filterItems);
var indexes = [], i = 0;
dataviewStore.each(function(item, index){
if(item) {
if(item.data.columnId == columnId) {
indexes[i++] = index;
}
}
}, this);
dataviewStore.remove(indexes);
this is my example if your record is matches with the value then store the index of that item after storing indexes of all the items and remove them.
Otherwise you have to use for loop and remove them from end of the array.
so I have writing a function that returns objects on the stage and puts them into an array. and the function works fine until i call the function on more than one object name, meaning if im in the root class, and I call this function on object1 lets say it will add all the object one's from the stage, but if i call it on object2 it will throw an error, which makes some sense, i guess it means that it is not adding it to a unique array, but im not sure how to do that.
would it be a good idea to maybe make a multidimensional array? if that is the case would it be too slow?
here is the function code:
public function findObjects(objectName, objLocation, bVisible = false):Array{
for (var i = 0; i < objLocation.numChildren; i++){
var nObj=objLocation.getChildAt(i);
if (nObj is objectName){
// add to array and make invisible
obj.push(nObj);
nObj.visible=bVisible;
}
}
return obj;
}
any help with this would be greatly appreciated.
Try this:
public function findObjects(type:Class, target:DisplayObjectContainer, bVisible:Boolean=false):Array
{
var out:Array = [];
for(var i:int = 0; i<target.numChildren; i++)
{
var obj:DisplayObject = target.getChildAt(i);
if(obj is type)
{
out.push(obj);
obj.visible = bVisible;
}
}
return out;
}
And then based on your code, the implementation would probably be:
obj = findObjects(MovieClip, container);
I know how to remove duplicates from an array, but what I'm trying to do is prevent an item from ever being added to an array in the first place if it already exists. I'm pulling in data from an xml feed in a loop, and I thought that searching for that values index would work, but no matter what, the index is always -1. Here's my code:
var yearArr:Array = new Array();
for (var i=0;i<numCovers;i++){
var coverRef = xmlObj.cover[i];
var coverClip:MovieClip = new MovieClip();
coverClip.year = coverRef.#year;
if (yearArr.indexOf(coverClip.year === -1)){
yearArr.push (coverClip.year);
}
}
Maybe I'm misunderstanding the indexOf function, but I thought it was supposed to return -1 if a value did not exist in an array. What am I doing wrong?
Here's the solution I came up with:
var yearArr:Array = new Array();
for (var i=0;i<numCovers;i++){
var coverRef = xmlObj.cover[i];
var coverClip:MovieClip = new MovieClip();
coverYear = coverRef.#year;
addCoverYear(coverYear);
}
function addCoverYear(coverYear:int):void {
if (yearArr.indexOf(coverYear) == -1){
yearArr.push(coverYear);
}
}
you can reduce an array by passing everything to a dictionary, which will automatically remove redundancies. then pass the dictionary back as a new array.
//Reduce Array
private function reduceArray(array:Array):Array
{
var dictionary:Dictionary = new Dictionary();
for each (var element:String in array)
dictionary[element] = true;
var result:Array = new Array();
for (var key:String in dictionary)
result.push(key);
dictionary = null;
return result;
}
Your code is almost fine. The problem is that an E4X property .#year is not a literal string (I'm not sure right now, but I believe it's an XMLList object). That's why the indexOf call will keep returning -1, because it is looking for a duplicate of that object, not a string. E4X will convert it to a string as soon as you put it somewhere where only strings can go, but until that time it is something else.
If you rewrite your code like this, it should work right away:
var yearArr:Array = new Array();
for each (var coverRef : XML in xmlObj.cover){
var year : String = coverRef.#year; // force the property to be a string
if (yearArr.indexOf(year) < 0){
yearArr.push (year);
}
}
There were also a few other optimizations you could do to your code. The new MovieClip() part wasn't used, not all variables were strongly typed and by using a for each loop, you can state much clearer what objects you're looping through.
Here is what you could do, if for example, you have an array of strings.
var ItemList:Array = new Array();
for each(var Item:String in UseYourXMLFeed)
{
if(ItemList.indexOf(Item) == -1)
{
ItemList.push(Item);
}
}
Edit:
Anyways, your real answer is in the comment by Sam.