Remove duplicate objects, but push property to array on remaining object - javascript

I have an array of objects like so:
[
{
"id": "1",
"location": "US"
},
{
"id": "7",
"location": "US"
},
{
"id": "1",
"location": "France"
},
{
"id": "1",
"location": "China"
}
]
I would like to end up with a resulting array that looks like this:
[
{
"id": "1",
"locations": ["US", "France", "China"]
},
{
"id": "7",
"locations": ["US"]
}
]
Is there a solid way to accomplish this using underscore?
I'm contemplating looping through the array and for each id looping through the rest of the array and pushing location values to a locations array on that first object (by id), then at the end removing all duplicate objects (by id) which do not contain a locations property.
This is different from existing questions on SO that simply ask about removing duplicates. I am aiming to remove duplicates while also holding on to certain property values from these duplicates in an array on the 'surviving' object.

Solution in plain Javascript
var data = [{ "id": "9" }, { "id": "1", "location": "US" }, { "id": "7", "location": "US" }, { "id": "1", "location": "France" }, { "id": "1", "location": "China" }],
result = [];
data.forEach(function (a) {
a.location && !result.some(function (b) {
if (a.id === b.id) {
b.locations.push(a.location);
return true;
}
}) && result.push({ id: a.id, locations: [a.location] });
});
document.write('<pre>' + JSON.stringify(result, 0, 4) + '</pre>');

You can use reduce function to transform your array.
var data = [
{ "id": "1", "location": "US" },
{ "id": "7", "location": "US" },
{ "id": "1", "location": "France" },
{ "id": "1", "location": "China" }
];
var result = data.reduce(function (prev, item) {
var newItem = prev.find(function(i) {
return i.id === item.id;
});
if (!newItem) {
prev.push({id: item.id, locations: [item.location]});
} else {
newItem.locations.push(item.location);
}
return prev;
}, []);

And a version using underscore:
var result = _.chain(data)
.groupBy('id')
.map(function(group, id){
return {
id: id,
locations: _.pluck(group, 'location')
}
})
.value();

Related

Replacing Data in Array

I am working on an angular application. I have an array as follows:
[{
"Name": "Andy"
},
{
"Name": "Bayer"
},
{
"Name": "James"
},
{
"Name": "Doda"
}]
I have another array which containes data as follows:
[
{
"Name": "Andy",
"Id": "1",
"Time": "2020-06-19T11:02+00:00"
},
{
"Name": "Billy",
"Id": "2",
"Time": "2020-06-19T11:05+00:00"
},
{
"Name": "Ciena",
"Id": 5
"Time": "2020-06-19T11:05+00:00"
},
{
"Name": "Doda",
"Id": "4",
"Time": "2020-06-19T11:05+00:00"
}
]
I want a resultant array such that code should check if Name is present in first array, then it should copy data from second array for that Name and push it in resultant array. For example common name between above two array is Andy and Doda, so data from Andy and Doda should be pushed to resultant array as follows:
[{
"Name": "Andy",
"Id": "1",
"Time": "2020-06-19T11:02+00:00"
},
{
"Name": "Bayer"
},
{
"Name": "James"
},
{
"Name": "Doda",
"Id": "4",
"Time": "2020-06-19T11:05+00:00"
}]
At run time I may get many names so code should be generic. I was trying following code which I got over stackoverflow itself
this.newArray = _.map(this.resultantArray, item => {
const value = _.find(this.dataArray, ['Name', item]);
const obj = value ? value : {Name: item};
return obj;
});
But this code is not working as expected as it works fine for the first time but when data comes for second time it appends data to previous data. I want array to be populated again freshly every time I send data. Please help
You can do this with vanilla JS no need for lodash. You can first map it and inside that you can find the value from second array otherwise return the current object:
var arrayTwo = [ { "Name": "Andy", "Id": "1", "Time": "2020-06-19T11:02+00:00" }, { "Name": "Billy", "Id": "2", "Time": "2020-06-19T11:05+00:00" }, { "Name": "Ciena", "Id": "5", "Time": "2020-06-19T11:05+00:00" }, { "Name": "Doda", "Id": "4", "Time": "2020-06-19T11:05+00:00" } ];
var arrayOne = [{ "Name": "Andy"}, { "Name": "Bayer"}, { "Name": "James"}, { "Name": "Doda"}];
var result = arrayOne.map(val=>arrayTwo.find(p=>p.Name==val.Name) || val);
console.log(result);
Suppose first array name is First
First : any [] = [{"Name": "Andy"},{"Name": "Bayer"},{ "Name": "James"},{"Name": "Doda"}]
And Second array name is Second
Second : any[] = [{"Name": "Andy","Id": "1","Time": "2020-06-19T11:02+00:00"},{"Name": "Bayer"},{"Name": "James"},{"Name": "Doda","Id": "4","Time": "2020-06-19T11:05+00:00"}]
Now do looping and check each name of first if its exists in second copy from second and push in result array
result : any[] =[];
this.First.forEach((element) => {
let index = this.Second.findIndex((x) => element.Name== x.Name);
if (index > -1) {
let data = {
this.Second[index].Name,
this.Second[index].Id,
this.Second[index].time,
};
this.result.push(data);
}
}

Javascript filter for multidimensional json object

Can't use javascript filter in multi-dimensional object.
var object = [{
"id": "1",
"name": "General",
"cards": [{
"id": "1",
"name": "shawn"
}, {
"id": "2",
"name": "neo"
}]
}, {
"id": "2",
"name": "CEO",
"cards": [{
"id": "1",
"name": "Raman"
}, {
"id": "2",
"name": "Sheena"
}]
}]
function searchFor(item) {
return item.cards.filter(
(card) => {
return card.name.indexOf("Raman") !== -1;
}
);
}
var filtered = object.filter(searchFor);
console.log(filtered);
This is how I am trying, inside the searchFor card.name I am getting the correct card name but filtering is returning all the cards.Its not filtering.
Could any help me with this.
An empty array isn't considered falsey in Javascript. So instead of returning the result of filtering the cards array, test its length.
var object = [{
"id": "1",
"name": "General",
"cards": [{
"id": "1",
"name": "shawn"
}, {
"id": "2",
"name": "neo"
}]
}, {
"id": "2",
"name": "CEO",
"cards": [{
"id": "1",
"name": "Raman"
}, {
"id": "2",
"name": "Sheena"
}]
}]
function searchFor(item) {
return item.cards.filter(
(card) => {
return card.name.indexOf("Raman") !== -1;
}
).length != 0;
}
var filtered = object.filter(searchFor);
console.log(filtered);
You were returning the filtered array, which would produce a TRUE result whenever cards existed. So you can just turn that into a boolean, by saying when the item.cards.filter(...).length > 0.
var object = [{
"id": "1",
"name": "General",
"cards": [{
"id": "1",
"name": "shawn"
}, {
"id": "2",
"name": "neo"
}]
}, {
"id": "2",
"name": "CEO",
"cards": [{
"id": "1",
"name": "Raman"
}, {
"id": "2",
"name": "Sheena"
}]
}]
var searchFor = (card) => card.name.indexOf("Raman") > -1;
var filteredCards = object.reduce((cards, item) => cards.concat(item.cards.filter(searchFor)), []);
var filteredObj = object.map(i => {
i.cards = i.cards.filter(searchFor);
return i;
}).filter(i => i.cards.length)
console.log(filteredCards, filteredObj)
Updated
I updated the code snippet to produce either the cards which were found. I also provide a method for returning all objects which contain the needed cards, and filter out the other cards.
// HTML Part
<div class="filter-list">
<button class="filter" data-filter-key="all">all</button>
<button class="filter" data-filter-key="open">open</button>
<button class="filter" data-filter-key="done">done</button>
</div>
// CSS Part
.filter:hover,
.filter:focus,
[data-active-filter="all"] .filter[data-filter-key="all"],
[data-active-filter="done"] .filter[data-filter-key="done"],
[data-active-filter="open"] .filter[data-filter-key="open"] {
text-decoration: underline;
}
[data-active-filter="open"] [data-completed="true"],
[data-active-filter="done"] [data-completed="false"] {
display: none;
}
// Script Part
(function () {
const mainNode = document.querySelector("main");
const filters = document.querySelector(".filter-list");
for (const filter of filters.children) {
filter.addEventListener("click", () => {
mainNode.setAttribute(
"data-active-filter",
filter.getAttribute("data-filter-key")
);
});
}
mainNode.setAttribute("data-active-filter", "all");
})();

How to merge and flat arrays at the same time

I have two arrays of data, one has tree structure and another is just a nested array with details..
What I want to do now is to flat this details array and merge it to tree's structure.
Both details and tree have records with same unique ID.
var tree = [{
"Children": [{
"Children": [],
"ID": "1",
"PendingChange": true,
}],
"ID": "22",
"PendingChange": false,
}];
var details = [{
"Address": {
"Jurisdiction": {
"Name": "United Kingdom"
},
"City": "Waltham Cross"
},
"ID": "1",
"Name": "J"
}];
var finalArray = _.map(tree, function(e) {
return _.extend(e, _.omit(_.findWhere(details, {
ID: e.ID
}), 'ID'));
});
console.log(finalArray);
<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
Desired output
var tree = [{
"Children": [{
"Children": [],
"ID": "1",
"PendingChange": true,
"Name": "J"
"Address_City": "Waltham Cross"
"Address_Jurisdiction_Name": "United Kingdom"
}],
"ID": "22",
"PendingChange": false,
}];
Underscore is not a must, I am just stuck with it - https://jsfiddle.net/ey8hqn19/
You could create recursive function with for...in loop that will loop deep tree object and then use find to find object with same id in details and add properties.
var tree = [{
"Children": [{
"Children": [],
"ID": "1",
"PendingChange": true,
}],
"ID": "22",
"PendingChange": false,
}];
var details = [{
"Address": {
"Jurisdiction": {
"Name": "United Kingdom"
},
"City": "Waltham Cross"
},
"ID": "1",
"Name": "J"
}];
function makeTree(data) {
for (var i in data) {
if (typeof data[i] == 'object') makeTree(data[i])
if (i == 'ID') {
var f = details.find(function(e) {
return e.ID == data[i]
})
if (f) {
Object.assign(data, {
"Name": f.Name,
"Address_City": f.Address.City,
"Address_Jurisdiction_Name": f.Address.Jurisdiction.Name
})
}
}
}
}
makeTree(tree)
console.log(tree)

Hierarchical json to flat with parent ID

I have Hierarchical JSON and want to convert to flat JSON without parent child.
vm.str = [
{
"s_gid": 0,
"title": "scholastic Master List 2016",
"nodes": [
{
"Id": "1",
"templateId": "1",
"s_gid": "10",
"m_s_p_id": "1",
"subject_group_name": "xxxxxxx",
"parent_id": "1",
"sname": "",
"nodes": [
{
"Id": "2",
"templateId": "1",
"s_gid": "100",
"m_s_p_id": "0",
"subject_group_name": "abc",
"parent_id": "10",
"sname": "",
"nodes": [
{
"Id": "3",
"templateId": "1",
"s_gid": "1000",
"m_s_p_id": "0",
"subject_group_name": "efg",
"parent_id": "100",
"sname": ""
}
]
}
]
}
]
}
]
what to convert to new vm.str2 = [] as flat, all nodes at same level without nodes ... sub nodes..
You can use recursive function to return one array of objects
var arr =[{"s_gid":0,"title":"scholastic Master List 2016","nodes":[{"Id":"1","templateId":"1","s_gid":"10","m_s_p_id":"1","subject_group_name":"xxxxxxx","parent_id":"1","sname":"","nodes":[{"Id":"2","templateId":"1","s_gid":"100","m_s_p_id":"0","subject_group_name":"abc","parent_id":"10","sname":"","nodes":[{"Id":"3","templateId":"1","s_gid":"1000","m_s_p_id":"0","subject_group_name":"efg","parent_id":"100","sname":""}]}]}]}]
function flatten(data) {
var result = [];
data.forEach(function(o) {
var obj = {}
for(var e in o) {
(Array.isArray(o[e])) ? result.push(...flatten(o[e])) : obj[e] = o[e];
}
result.push(obj)
})
return result;
}
console.log(flatten(arr))
You could use Array.prototype.reduce() plus recursion for this task:
function getNodes(inputArr) {
return inputArr.reduce(function (prev, value) {
return prev.concat(
[ value ],
(value.nodes ? getNodes(value.nodes) : [])
);
}, []);
}
If you still want to remove nodes, you could either use Array.prototype.map or even Array.prototype.each:
output = output.map(function (value) {
value.nodes = undefined;
return value;
});

Underscore filter array of object using like query

I have the below Json.
{
"results": [
{
"id": "123",
"name": "Some Name"
},
{
"id": "124",
"name": "My Name"
},
{
"id": "125",
"name": "Johnson Johnson"
},
{
"id": "126",
"name": "Mike and Mike"
},
{
"id": "201",
"name": "abc xyz"
},
{
"id": "202",
"name": "abc befd"
},
{
"id": "210",
"name": "jki yuiu"
},
{
"id": "203",
"name": "asdfui uiuu"
},
{
"id": "204",
"name": "sfdhu uiu"
},
{
"id": "205",
"name": "asdfui uyu"
}
]
}
Using Underscore i want to filter the above data using sql like query on id.
for example if pass "2" the json should be filtered and return a new json which contain id starting with 2, If i pass 20 it should return new json with id starting with 20
similar to sql like query and then return n results matching,
correction: I want the data starting with id 2 or whatever parameter i pass i need data starting with it
Try this
function getResult(keyToFilter, valueStartsWith){
return _.filter(results, function(d){ return d[keyToFilter].startsWith(valueStartsWith); })
}
getResult("name", "asdfui");
[{
"id": "203",
"name": "asdfui uiuu"
},
{
"id": "205",
"name": "asdfui uyu"
}]
What about Array.prototype.filter and Array.prototype.slice? (underscore has similar functions but why to use them when it can be solved with plain JS)
function sqlLikeFilter(data, id, maxn) {
return data.result.filter(function(x) { return x.id == id; }).slice(0, maxn);
}
console.log(sqlLikeFilter(yourData, 125, 1));
Try this
function(id){
var result = _.filter(results, function(value) {
return value.id === id
})
return result;
}

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