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Remove all duplicate object elements from array

This one's been giving me problems for a week, cross my fingers one of you can help me here...
This application was built on Laravel and the front scaffolded using Vue.
Thing is I have an array of objects that is supposed to be sent to the backend in order for it to be stored in a database. Thing is this is an editor and the idea is not reload the page every time something is changed, so here comes my problem...
The way of getting the information is through window.postMessage(), so it seems the information lingers on even after saving, since the page behavior is for it to not reload, I have tried emptying the array after firing the save function. Now it works the first time because the array is empty so there's nothing to compare it to, it also works the second time, but from the third time on, it duplicates some of the objects inside and stores them in DB.
Here's my code:
saveNewSettings() {
//THIS IS THE ARRAY I NEED TO EMPTY (ALREADY DECLARED IN THE DATA OBJECT)
/* this.newItems = [
{ id="123", name="a", otherProps="someProps" },
{ id="456", name="ab, otherProps="someProps" },
{ id="789", name="c", otherProps="someProps" },
]
*/
//THIS IS THE AN EMPTY ARRAY I'M USING TO COMPARE LATER ON... (ALREADY DECLARED IN THE DATA OBJECT)
// this.newlyCreatedItems = [];
if ( !this.newlyCreatedItems.length ) {
this.newlyCreatedItems = this.newItems;
} else {
for ( let i = 0; i < this.newItems.length; i++ ) {
for ( let j = 0; j < this.newlyCreatedItems.length; j++ ) {
if ( this.newItems[i].id == this.newlyCreatedItems[j].id ) {
this.newItems.splice( i, 1 );
}
}
}
}
//THIS IS THE SERVICE I USE TO SEND THE INFO TO THE BACK END
//THIS ONE HAS BEEN IMPORTED FROM AN SERVICE FILE
settingsService.save( this.newItems )
.then(response => {
//WHAT TO DO AFTER THE RESPONSE GOES HERE
});
}
So here's the thing, firing the function for the first time, since it's the first, doesn't duplicate anything in the database... For the second time, it works well and it only saves the new item, from the third time on, it starts duplicating.
If you need me to elaborate more, just let me know, I thank you all in advance...

Quick and dirty using jQuery:
var names = ["Mike","Matt","Nancy","Adam","Jenny","Nancy","Carl"];
var uniqueNames = [];
$.each(names, function(i, el){
if($.inArray(el, uniqueNames) === -1) uniqueNames.push(el);
});

You tagged vue.js but this problem statement is more like from JavaScript side. Basically, You are doing shallow copy of the newItems array into the newlyCreatedItems array which causing the updation issue as both are referencing to the same pointer address.
You can resolve this issue by deep copying with the help of structuredClone() method.
Live Demo :
let newItems = [
{ id: "123", name: "a", otherProps: "someProps" },
{ id: "456", name: "ab", otherProps: "someProps" },
{ id: "789", name: "c", otherProps: "someProps" }
];
let newlyCreatedItems = [];
function saveNewSettings() {
if (!newlyCreatedItems.length ) {
newlyCreatedItems = structuredClone(newItems);
} else {
for ( let i = 0; i < newItems.length; i++ ) {
for ( let j = 0; j < newlyCreatedItems.length; j++ ) {
if ( newItems[i].id == newlyCreatedItems[j].id ) {
newItems.splice( i, 1 );
}
}
}
}
}
saveNewSettings();
console.log(newlyCreatedItems);
console.log(newItems);
console.log('-------');
saveNewSettings();
console.log(newlyCreatedItems);
console.log(newItems);

JavaScript / AngularJS modify property in array

I have the following AngularJS model:
$scope.Model = {
Users : [{
UserId: '',
FirstName: '',
LastName: ''
}],
Products :[{
ProductId: '',
Price: ''
}]
};
If I populate this array with N users, and one user has id=1, how can I update that specific user (with id=1) the property LastName?
So for example if I will get a new AngularJS model:
$scope.UserToUpdate ={
UserId: 1,
LastName: "Smith"
};
I want to loop through the $scope.Model array and update the user with id=1 but only the FirstName property.
P.S. I don't know at what position the target user object in the array it is so basically can be at $scope.Model.Users[0] or $scope.Model.Users[1] or $scope.Model.Users[10] or at $scope.Model.Users[N] ...

You can just loop through your list of users
for (var i = 0; i < $scope.Model.Users.length; i++) {
if($scope.Model.Users[i].UserId === $scope.UserToUpdate.UserId) {
$scope.Model.Users[i].LastName = $scope.UserToUpdate.LastName;
break;
}
}
EDIT: Actually harish's answer is on to something too. Here's another solution using $filter:
var matchedUsers = $filter('filter')($scope.Model.Users, { UserId: $scope.UserToUpdate.UserId });
if (matchedUsers.length > 0) {
matchedUsers[0].LastName = $scope.UserToUpdate.LastName;
}
And don't forget to add the $filter service as a parameter in your controller declaration for this second solution.

$scope.UserToUpdate =
$scope.Model.Users.filter(function(user) { return user.FirstName == "test"; })[0];
BTW: you can add a check if the user exists..

you can use $filter
var user = $filter('filter')($scope.Model.Users, 'UserId == 1');
you are read more about $filter('filter') here

Try this! working demo http://plnkr.co/edit/scyV79HqqA7nOG9h4ezH?p=preview . Please check the console log.
angular.forEach($scope.Model[0].Users, function(value1, key1) {
var i = 0;
angular.forEach(value1, function(value, key) {
if (key == 'UserId' && $scope.UserToUpdate.UserId == value) {
$scope.Model[0].Users[i].LastName = $scope.UserToUpdate.LastName;
}
i++;
});
});
The above code updating the Model object LastName property based on UserToUpdate object (id=1)

How can i send objects as parameter Javascript

I need to pass an array as parameter but i have a problem, i dont know how to explain it so here is the example:
I have this code:
var doc = document;
var Class = {};
Class.Validate = function(opc)
{
alert(opc.id);//
return Class;// when returns the object the alert trigger as expected showing "#name"
};
Class.Validate({
id: "#name",
})
But what im trying to do is this:
var Class = {};
Class.Validate = function(opc)
{
alert(opc.name);//when the object is return show display "carlosmaria"
return Class;//
};
Class.Validar({
name: {field:"carlos",field:"maria"},
})
how can i archived that?

alert(opc.name) should return something like {Object object} because it's an objet. The second point is that your object has twice "field" as property.
If you want to use an array, you should call this way:
Class.Validar({
name: ["carlos", "maria"]
})
Then, you could loop over opc.name to concatenate a full name. Something like this:
Class.Validate = function(opc)
{
var name = "";
for (var i=0, len=opc.name.length; i<len; ++i) {
name += opc.name[i];
}
alert(name);//when the object is return show display "carlosmaria"
return Class;//
};

Consider using actual arrays (via array literals):
Class.Validate({
name: ["carlos", "maria"]
});

Look for a value for a given key in JSON and change the value using javascript

I am looking to write a function which can look up a value based on a key and replace that value with another. The key is a tree from the start node of JSON. Here is the example.
var myData = {
name : 'Dan',
address: {
city : 'Santa Clara',
details : {
'prevhouse' : ''
}
}
}
Input to the function is a key tree. For eg, myData-address-details-prevhouse
When I pass this key with a new value, say 'Texas', the prevhouse value will get changed to the new value I am sending.
and new JSON will be
var myData = {
name : 'Dan',
address: {
city : 'Santa Clara',
details : {
'prevhouse' : 'Texas'
}
}
}
Here is what I wrote so far
var tree = key.split("-");
now the tree variable contains ["myData","address", "details","prevhouse"]
I know that we can access the object using myData[tree[0]][tree[1]][tree[2]], but somehow not able to get it dynamic from parsed value.
how do we generate this dynamically since the length of the depth is not known till runtime.
Hope to get a help.

try with this code:
var myData = {
name: 'Dan',
address: {
city: 'Santa Clara',
details: {
prevhouse: ''
}
}
};
function setAttribute(obj, key, value) {
var i = 1,
attrs = key.split('-'),
max = attrs.length - 1;
for (; i < max; i++) {
attr = attrs[i];
obj = obj[attr];
}
obj[attrs[max]] = value;
console.log('myData=', myData);
}
setAttribute(myData, "myData-address-details-prevhouse", "Texas");
here a working jsfiddle demo; see the console for the result

You should be able to iterate through each key because your JSON is just a JS object. So go through each key, check if it's defined, if it is, use that object for your next check. That'll get you where you want to go. Keep in mind you'll be setting the last key to your value.
basic psuedo-code without dealing with setting:
obj = data;
for (key in keys) {
obj = obj[key]
}

Something like this would do:
function update(node, path, value) {
path = path.split('-');
do {
node = node[path.splice(0, 1)];
} while(path.length > 1);
node[path[0]] = value;
}

Given that myData is the object, I think you should be using myData[tree[1]][tree[2]][tree[3]] and throwing away the first item in the array.
Something like this should work recursively (untested)
function updateValue(obj, key, value)
{
var keys = key.split('-');
updateObjectValue(obj, keys.shift(), value);
}
function updateObjectValue(obj, keyArray, value)
{
if (keyArray.length == 1) {
obj[keyArray[0]] = value;
}
else if (keyArray.length > 1) {
updateObject(obj[keyArray[0]], keyArray.shift(), value);
}
}

add property to nested array in mongodb document

I have a mongodb document with the following structure
> db.user.find().limit(1);
{ "_id" : "1", "foo" : { "bars" : [
{
"name" : "bar1"
},
{
"name" : "bar2"
},
], ... }, ... }
I want to add a new property to each bar. I've got my script iterating over the bars array, but I can't get the new property in there, how can I do this?
var users = db.user.find({"foo.bars":{$exists:true}});
users.forEach(function(user) {
user.foo.bars.forEach(function(bar)
{
printjson(bar);
//how can I specify the current 'bar' in this update?
//db.experience.update({_id: user._id}, {$set: {"what goes here?" : "newbarValue"}});
});
});

So says the preacher man:
var users = db.user.find({"foo.bars":{$exists:true}});
users.forEach(function(user) {
var id = user._id;
var foo_bars = user.foo.bars;
var new_foo_bars = [];
for(var i = 0; i < foo_bars.length; i++) {
var foo_bar = foo_bars[i];
foo_bar['newkey'] = 'newvalue';
new_foo_bars.push(foo_bar);
}
db.user.update({"_id":id}, {$set:{"foo.bars":new_foo_bars}});
});

I have noticed that you are scrolling through the array on the client side there in JS.
If you were to form a new "bars" array from the old one then push it in as a whole new value this would mean you only do one DB call and the code is quite elegant.
If MongoDB does not support it normally it is better to just do the work on the client side.

You have to update each element of the nested document individually. Using the positional operator '$' will not work since it will only work on the first match (as documented).