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Javascript - Push to a new array dynamically?

Hello I am new to javascript so I'm sorry in advance if my explanation is not the best.
I am getting my data back from an array called myData. I have a condition statement which checks the page url and depending on the url I am pushing a specific index of an array to a new array called stateArray
At the moment I am using the push method like this:
stateArray.push(myData[1][5], myData[2][5], myData[3][5], myData[4][5], myData[5][5], myData[6][5], myData[7][5], myData[8][5], myData[9][5], myData[10][5], myData[11][5], myData[12][5], myData[13][5], myData[14][5], myData[15][5], myData[16][5], myData[17][5], myData][5])
the return of stateArray is giving back the data I am expecting but I am going to have ten different conditions and would like to know if there is a way of doing the push 17 times for every condition better?
Every element is the same for the condition. For example
if (url.includes('/states/') {
stateArray.push(myData[1][5], myData[2][5], myData[3][5], myData[4][5], myData[5][5], myData[6][5], myData[7][5], myData[8][5], myData[9][5], myData[10][5], myData[11][5], myData[12][5], myData[13][5], myData[14][5], myData[15][5], myData[16][5], myData[17][5], myData][5])
} else if (url.includes('/homes/) {
stateArray.push(myData[1][6], myData[2][6], myData[3][6], myData[4][6], myData[5][6], myData[6][6], myData[7][6], myData[8][6], myData[9][6], myData[10][6], myData[11][6], myData[12][6], myData[13][6], myData[14][6], myData[15][6], myData[16][6], myData[17][6], myData][6])
} else if (url.incldues('/retail/) {
stateArray.push(myData[1][7], myData[2][7], myData[3][7], myData[4][7], myData[5][7], myData[6][7], myData[7][7], myData[8][7], myData[9][7], myData[10][7], myData[11][7], myData[12][7], myData[13][7], myData[14][7], myData[15][7], myData[16][7], myData[17][5], myData][7])
}
Like I mentioned earlier I currently have 10 conditions and it is very difficult to maintain and update. Is there a way of generating the same results dynamically? I believe this can be done through a loop but I am not familiar with the syntax in regards to pushing at a specific index and ending at a specific index.
My expected outcome is a short handed way of going through each condition and pushing into the new Array.

You can use forEach:
if (url.includes('/states/')) {
myData.forEach(e => stateArray.push(e[5]));
} else if (url.includes('/homes/')) {
myData.forEach(e => stateArray.push(e[6]));
} else if (url.includes('/retail/')) {
myData.forEach(e => stateArray.push(e[7]));
}
(Also note you need a second ) at the end of your if to close off both the if and the includes)

removing objects in an object in an array javascript

I've done some research on this issue. I am trying to manipulate an array of calculated values that looks like this in the console:
{nodeVoltages: Array(11), totalPower: Array(1), xlength: Array(11)}
nodeVoltages: Array(11)
0:48
1:47.71306060387108
2:47.250273223993105
3:46.59686907269243
4:45.71876416434013
5:44.53304242029258
6:42.745236969423615
7:Complex {re: 40.38334500994142, im:1.919295696316476, __ember1513267958317: "ember368"}
8:Complex { re:39.55961661806138, im:3.8933604519196416, __ember1513267958317: "ember369"}
This array is created dynamically through some math that I've come up with so there is no input data that I can give you. I'm trying to make the above array look like this:
{nodeVoltages: Array(11), totalPower: Array(1), xlength: Array(11)}
nodeVoltages: Array(11)
0:48
1:47.71306060387108
2:47.250273223993105
3:46.59686907269243
4:45.71876416434013
5:44.53304242029258
6:42.745236969423615
7:40.38334500994142
8:39.55961661806138
Using mathjs, I was able to evaluate my expressions and dynamically add the values into an array with the array.push command and display them. However, my code breaks once the imaginary values pop up in the results of my array.
How can I remove these imaginary numbers from my array? In other words, I need to remove the "im:" parts of the values when they begin to appear before I push them to the displayed array.
I tried to do this with some code I found from a previous answer to someone else's question (How do I remove a particular element from an array in JavaScript?) splice command like this:
var nodeVoltage2 = parser.eval(expression2);
//checks if there are imaginary values and removes them
if ("im" in nodeVoltage2) {
nodeVoltage2.splice(2,1)
}
//adds value to result array for analysis
nodeVoltages.push(nodeVoltage2);
but it returns in the console that "im is not defined".
Any help is greatly appreciated!

You can use the array map function.
Basically, we loop through the array. If the item has a .re property, we take that value only. If there is no .re property, we keep the value as is.
We can either write that in shorthand, as with result using the ternary operator and arrow function, or we can write it in a slightly more verbose but traditional way, as with resultTwo
let data = [
48
,47.71306060387108
,47.250273223993105
,46.59686907269243
,45.71876416434013
,44.53304242029258
,42.745236969423615
,{re: 40.38334500994142, im:1.919295696316476, __ember1513267958317: "ember368"}
,{ re:39.55961661806138, im:3.8933604519196416, __ember1513267958317: "ember369"}
]
let result = data.map((x) => x && x.re ? x.re : x);
let resultTwo = data.map(function(elem) {
// First, we need to check that the array element is not null / undefined
// We then need to check that it has a property called re that is also not null / undefined
if (elem != null && elem.re != null) {
// Just return the property we're interested in
return elem.re;
} else {
// Return the element as is
return elem;
}
});
console.log(result);
console.log(resultTwo);

How to check if an Object already exists in an Array before adding it?

I have this algorithme issue, I would like to check if an Object is already present in my Array before adding it.
I tried many different approaches (indexOf, filter...), and my last attempt is with an angular.foreach.
The problem is my $scope.newJoin remains always empty. I understood why, it's because the if is never read, because of the 0 size of my $scope.newJoin, but I don't know how to figure this out...
$scope.newJoinTMP is composed by : 6 Objects, within each a timePosted attribute (used for compare these different array Objects).
$scope.newJoin is an empty Array. I want to fill it with the Objects inside $scope.newJoinTMP but with the certainty to have once each Objects, and not twice the same ($scope.newJoinTMP can have duplicates Objects inside, but $scope.newJoin mustn't).
angular.forEach($scope.newJoinTMP, function(item)
{
angular.forEach($scope.newJoin, function(item2)
{
if (item.timePosted === item2.timePosted)
{
//snap.val().splice(snap.val().pop(item));
console.log("pop");
}
else
{
$scope.newJoin.push(item);
console.log("newJoin :", $scope.newJoin);
}
});
});

if(!$scope.newJoin.find(el=>item.timePosted===el.timePosted){
$scope.newJoin.push(item);
console.log("newJoin :", $scope.newJoin);
}
You dont want to push inside an forEach, as it will push multiple times...

There might be better ways to handle your particular situation but here's a fix for your particular code.
Replaced your inner for each with some which returns boolean for the presence of element and by that boolean value, deciding whether to add element or not
angular.forEach($scope.newJoinTMP, function(item)
{
var isItemPresent = $scope.newJoin.some(function(item2)
{
return item.timePosted === item2.timePosted;
//you dont need this conditional handling for each iteration.
/* if (item.timePosted === item2.timePosted)
{
//snap.val().splice(snap.val().pop(item));
console.log("pop");
}
else
{
$scope.newJoin.push(item);
console.log("newJoin :", $scope.newJoin);
} */
});
if( ! isItemPresent ) {
$scope.newJoin.push(item);
} else {
//do if it was present.
}
});

If you want to avoid the nested loop (forEach, some, indexOf, or whatever) you can use an auxiliar object. It will use more memory but you will spent less time.
let arr = [{ id: 0 }, { id:0 }, { id: 1}];
let aux = {};
const result = arr.reduce((result, el) => {
if (aux[el.id] === undefined) {
aux[el.id] = null;
return [el, ...result];
} else {
return result;
}
}, []);
console.log(result);

You can use reduce
$scope.newJoin = $scope.newJoinTMP.reduce(function(c, o, i) {
var contains = c.some(function(obj) {
return obj.timePosted == o.timePosted;
});
if (!contains) {
c.push(o);
}
return c;
}, []);
The problem with your current code is, if newJoin is empty, nothing will ever get added to it - and if it isnt empty, if the first iteration doesn't match the current item being iterated from newJoinTMP - you're pushing.

can't get nested forEach to work in Javascript

So I guess the title is selfexplanatory. I have some code with nested forEach loops inside it. The loops are iterating over an array of chapter objects. Each object can have multiple child nodes and they again can have multiple child nodes, and so on.
I want to end up with one array which contains nested arrays with the child nodes.
So far my code looks like this:
exports.chapter = function(req, res) {
var chapters = [],
result = [];
chapters = exports.index(req, res);
chapters.forEach(function(chapter) {
if(chapter.orphan){
result.add({
'chapter': chapter,
'children': getChildren(chapter.children)
});
}
});
function getChildren(siblings) {
var children = [];
chapters.forEach(function(chapter) {
if($.inArray(chapter, siblings)){
children.add({
'chapter': chapter,
'children': getChildren(chapter.children)
});
}
});
return children;
};
};
I don't get any errors except for my page not loading. It doesn't write anything in my console. I think it's a problem in the setup but I'm unable to find out where at the moment. Really hope you guys can help.

Most likely problem is here:
if($.inArray(chapter, siblings)){
$.inArray is a horribly misnamed method: It returns an index, or -1 if not found, not a flag as the name implies. -1 is, of course, truthy; and 0 (a valid index), is falsey, so your if probably wants to be
if($.inArray(chapter, siblings) != -1){
// We found it...
}
or possibly
if($.inArray(chapter, siblings) == -1){
// We didn't find it
}

It's a bit strange.. I don't understand why you're using 'add' instead of 'push' method. If I try to "add" an object to an array I get an usual error. Don't you?

Compare Objects in Array and Remove Duplicate & Update - Javascript

I have an array of objects that presents as follows:
0: Object
ConsolidatedItem_catalogId: "080808"
ConsolidatedItem_catalogItem: "undefined"
ConsolidatedItem_cost: "0"
ConsolidatedItem_description: "Test Catalog Item"
ConsolidatedItem_imageFile: "27617647008728.jpg"
ConsolidatedItem_itemNumber: "1234"
ConsolidatedItem_quantity: "1"
ConsolidatedItem_source: "CAT"
ConsolidatedItem_status: "02"
ConsolidatedItem_umCode: "EA"
1: Object
ConsolidatedItem_catalogId: ""
ConsolidatedItem_catalogItem: "undefined"
ConsolidatedItem_cost: "0"
ConsolidatedItem_description: "ALARM,SHUTDOWN SYSTEM,AXIOM,XP3, 0-1500 PSIG, HIGH AND LOW PRES Testing"
ConsolidatedItem_imageFile: ""
ConsolidatedItem_itemNumber: "10008"
ConsolidatedItem_quantity: "1"
ConsolidatedItem_source: "INV"
ConsolidatedItem_status: "02"
ConsolidatedItem_umCode: "EA"
I'm trying to update and remove an object if it's added again, or update the object. Preferably update the object with the new value. My code is as follows:
var result = $.grep(finalObject, function(e) {
return e.ConsolidatedItem_itemNumber == o.ConsolidatedItem_itemNumber;
});
console.log(result);
if (result.length == 0) {
finalObject.push(o);
shoppingCounter = finalObject.length;
$('#numberShoppedItems').text(shoppingCounter);
console.log(finalObject);
} else if (result.length == 1) {
finalObject.filter(function(x){
result = x;
console.log(result);
return x == result.ConsolidatedItem_itemNumber;
});
} else {
alert('Multiples Found');
}
}
I've tried multiple ways of getting the exact object and manipulating the data, however they've all failed. I would prefer to update the object, say if CatalogItem_itemNumber held the same value, if the CatalogItem_quantity was different - add the CatalogItem_quantity values together and update the array of objects.
I don't need an exact answer, a nudge in the right direction would do wonders though. I've looked at several of the related questions over the past couple of hours but none of them seem to address the issue. If you know of a question that has an answer, feel free to just link that as well. I may have missed it.
No Underscore.js please

When you find the matching record, you may update it by using $.extend
$.extend(result[0], o)
This will update the object in finalObject array in-place.
Alternatively, if you want to use the filter, you will need to insert the new object in the array.
finalObject = finalObject.filter(function(x) {
return x !== result[0];
});
finalObject.push(o)
Here we are allowing all the records that are not not equal to result to be returned in the resultant array that is received in finalObject. In next line, we are adding the new record.

Solved in the following manner:
1.) Verify object is not empty.
2.) Use .some() on object to iterate through it.
3.) Check if the finalObject, which is now e, has a match for the key in my temporary object I assemble, o.
4.) Update the values that need updating and return true;
Note: Originally I was going to remove the object by its index and replace it with a new object. This too can work by using .splice() and getting the index of the current object in that array you're in.
Here is the updating version:
if (o.ConsolidatedItem_quantity != '') {
var result = $.grep(finalObject, function(e) {
return e.ConsolidatedItem_itemNumber == o.ConsolidatedItem_itemNumber;
});
if (result.length == 0) {...}
else {
finalObject.some(function (e) {
if(e.ConsolidatedItem_itemNumber == o.ConsolidatedItem_itemNumber){
var a;
a = +e.ConsolidatedItem_quantity + +o.ConsolidatedItem_quantity;
e.ConsolidatedItem_quantity = a.toString();
document.getElementById(o.ConsolidatedItem_itemNumber).value=a;
return true;
};
});
}
}