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Filter array present inside a array of objects without affecting the main array

I have JSON like below, I need to filter out workers having the age less than 25.
var employee = {
"value": [
{
"position": "Seniro Developer",
"description": "Developemwnt",
"workers": [
{
"name": "Kumar",
"age": 22
},
{
"name": "aravinth",
"age": 29
},
{
"name": "sathish",
"age": 35
}
]
},
{
"position": "Tester",
"description": "testing",
"workers": [
{
"name": "vinth",
"age": 18
},
{
"name": "rahul",
"age": 45
},
{
"name": "sathish",
"age": 12
}
]
}
]
}
I have tried to use the below code, but it returns all the value inside the workers array, but my expectation is it should return only the employee having than 25.
If I use Map function it is affecting the employee Object also.
var filteredResult = employee.filter(e => e.workers.some(w => w.age < 25))
Expected Result:
{
"value": [
{
"position": "Seniro Developer",
"description": "Developemwnt",
"workers": [
{
"name": "Kumar",
"age": 22
}
]
},
{
"position": "Tester",
"description": "testing",
"workers": [
{
"name": "vinth",
"age": 18
},
{
"name": "sathish",
"age": 12
}
]
}
]
}

You can do it with a map and a filter, to avoid to modify the original array, you can use Object.asign
var employee = {
"value": [{
"position": "Seniro Developer",
"description": "Developemwnt",
"workers": [{
"name": "Kumar",
"age": 22
},
{
"name": "aravinth",
"age": 29
},
{
"name": "sathish",
"age": 35
}
]
},
{
"position": "Tester",
"description": "testing",
"workers": [{
"name": "vinth",
"age": 18
},
{
"name": "rahul",
"age": 45
},
{
"name": "sathish",
"age": 12
}
]
}
]
}
var filteredResult = employee.value.map(e => {
let filter = e.workers.filter(w => w.age < 25)
return Object.assign({}, e, {workers: filter})
})
console.log('original', employee)
console.log('result', filteredResult)

You could reduce the array and check if the filtered workers have some elements then push a new object with changed workers to the result set.
var employee = { value: [{ position: "Seniro Developer", description: "Developemwnt", workers: [{ name: "Kumar", age: 22 }, { name: "aravinth", age: 29 }, { name: "sathish", age: 35 }] }, { position: "Tester", description: "testing", workers: [{ name: "vinth", age: 18 }, { name: "rahul", age: 45 }, { name: "sathish", age: 12 }] }] },
value = employee.value.reduce((r, o) => {
const workers = o.workers.filter(({ age }) => age < 25);
if (workers.length) r.push({ ...o, workers });
return r;
}, []),
result = { value };
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }

You can also try this:
var employee = { "value": [ { "position": "Seniro Developer", "description": "Developemwnt", "workers": [ { "name": "Kumar", "age": 22 }, { "name": "aravinth", "age": 29 }, { "name": "sathish", "age": 35 } ] }, { "position": "Tester", "description": "testing", "workers": [ { "name": "vinth", "age": 18 }, { "name": "rahul", "age": 45 }, { "name": "sathish", "age": 12 } ] } ]}
result = employee.value.map(({workers, ...rest})=>({...rest, workers:[...workers.filter(k=>k.age<25)]}));
console.log(result);

Use map and while creating the workers key in return object use filter to get employee with age less than 25. map will create an array
var employee = {
"value": [{
"position": "Seniro Developer",
"description": "Developemwnt",
"workers": [{
"name": "Kumar",
"age": 22
},
{
"name": "aravinth",
"age": 29
},
{
"name": "sathish",
"age": 35
}
]
},
{
"position": "Tester",
"description": "testing",
"workers": [{
"name": "vinth",
"age": 18
},
{
"name": "rahul",
"age": 45
},
{
"name": "sathish",
"age": 12
}
]
}
]
}
let filteredEmployee = employee.value.map((item) => {
return {
"position": item.position,
"description": item.description,
"workers": item.workers.filter(elem => elem.age < 25)
}
});
let newObject = Object.assign({}, {
value: filteredEmployee
});
console.log(newObject)

You can use map method with ... rest syntax:
employee.value.map(({workers, ...rest}) => ({...rest,
workers: workers.filter(w => w.age < 25)}));
An example:
let employee = {
"value": [
{
"position": "Seniro Developer",
"description": "Developemwnt",
"workers": [
{
"name": "Kumar",
"age": 22
},
{
"name": "aravinth",
"age": 29
},
{
"name": "sathish",
"age": 35
}
]
},
{
"position": "Tester",
"description": "testing",
"workers": [
{
"name": "vinth",
"age": 18
},
{
"name": "rahul",
"age": 45
},
{
"name": "sathish",
"age": 12
}
]
}
]
}
const result = employee.value.map(({workers, ...rest}) => ({...rest, workers: workers.filter(w => w.age < 25)}));
console.log(result);

How to use lodash to remove keys from a JSON object?

I've been trying to transform some data using lodash without success. I am really new to javascript and lodash. How can I get the expected result?
I've used mapValues and chain, but I didn't achieve anything good.
const data = {
"north": [
{
"2018-07-01": {
"date": "2018-07-01",
"name": "david",
"age": 11
},
"2018-07-02": {
"date": "2018-07-02",
"name": "damo",
"age": 16
},
"2018-07-03": {
"date": "2018-07-03",
"name": "dani",
"age": 12
}
}
],
"south": [
{
"2018-07-01": [
{
"fruit": "banana",
"date": "2018-07-01",
"name": "miller",
"age": 11
},
{
"fruit": "mango",
"date": "2018-07-01",
"name": "mano",
"age": 11
},
{
"fruit": "avocado",
"date": "2018-07-01",
"name": "karl",
"age": 14
}
],
"2018-07-02": [
{
"fruit": "pineaplle",
"date": "2018-07-02",
"name": "gautier",
"age": 12
},
{
"fruit": "apple",
"date": "2018-07-02",
"name": "gauteng",
"age": 9
},
{
"fruit": "watermelon",
"date": "2018-07-02",
"name": "garzier",
"age": 12
}
]
}
]
};
Below is the expected result. I am trying to remove the dates which are outside the objects and arrays.
const expectedData = {
"north": [
{
"date": "2018-07-01",
"name": "david",
"age": 11
},
{
"date": "2018-07-02",
"name": "damo",
"age": 16
},
{
"date": "2018-07-03",
"name": "dani",
"age": 12
}
],
"south": [
{
"fruit": "banana",
"date": "2018-07-01",
"name": "miller",
"age": 11
},
{
"fruit": "mango",
"date": "2018-07-01",
"name": "mano",
"age": 11
},
{
"fruit": "avocado",
"date": "2018-07-01",
"name": "karl",
"age": 14
},
{
"fruit": "pineaplle",
"date": "2018-07-02",
"name": "gautier",
"age": 12
},
{
"fruit": "apple",
"date": "2018-07-02",
"name": "gauteng",
"age": 9
},
{
"fruit": "watermelon",
"date": "2018-07-02",
"name": "garzier",
"age": 12
}
]
};

You don't really need lodash for this. You can look at each key in your data and the just pull the values from each element of the array and concat it into a new array.
const data = {"north": [{"2018-07-01": {"date": "2018-07-01","name": "david","age": 11},"2018-07-02": {"date": "2018-07-02","name": "damo","age": 16},"2018-07-03": {"date": "2018-07-03","name": "dani","age": 12}}],"south": [{"2018-07-01": [{"fruit": "banana","date": "2018-07-01","name": "miller","age": 11},{"fruit": "mango","date": "2018-07-01","name": "mano","age": 11},{"fruit": "avocado","date": "2018-07-01","name": "karl","age": 14}],"2018-07-02": [{"fruit": "pineaplle","date": "2018-07-02","name": "gautier","age": 12},{"fruit": "apple","date": "2018-07-02","name": "gauteng","age": 9},{"fruit": "watermelon","date": "2018-07-02","name": "garzier","age": 12}]}]};
Object.keys(data).forEach(k => {
data[k] = data[k].reduce((a, c) => a.concat(...Object.values(c)), [])
})
console.log(data)
This starts with each key in your original object north and south. And for each one replaces the array with the accumulated values of each object in that array ignoring the keys.

alternatively you could just do this
const expectedData = {
north: Object.values(data.north[0]),
south: Object.values(data.south[0])
}

You can do any lodash quick operations, in pure JS way. But, since you tagged lodash
here is the version:
_.mapValues(data, v => _.flatMapDeep(v, _.values))
var data = {
"north": [
{
"2018-07-01": {
"date": "2018-07-01",
"name": "david",
"age": 11
},
"2018-07-02": {
"date": "2018-07-02",
"name": "damo",
"age": 16
},
"2018-07-03": {
"date": "2018-07-03",
"name": "dani",
"age": 12
}
}
],
"south": [
{
"2018-07-01": [
{
"fruit": "banana",
"date": "2018-07-01",
"name": "miller",
"age": 11
},
{
"fruit": "mango",
"date": "2018-07-01",
"name": "mano",
"age": 11
},
{
"fruit": "avocado",
"date": "2018-07-01",
"name": "karl",
"age": 14
}
],
"2018-07-02": [
{
"fruit": "pineaplle",
"date": "2018-07-02",
"name": "gautier",
"age": 12
},
{
"fruit": "apple",
"date": "2018-07-02",
"name": "gauteng",
"age": 9
},
{
"fruit": "watermelon",
"date": "2018-07-02",
"name": "garzier",
"age": 12
}
]
}
]
};
var expectedData = _.mapValues(data, v => _.flatMapDeep(v, _.values));
console.log(expectedData);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

Filter nested JSON object with multiple arrays and store the filtered objects in an array

I want to filter the items array objects which match the "model" key in the models array and store them in an array. I did succeed in my attempt but I am not very satisfied with my effort. Are there any better ways of doing it?
Any suggestions on how to do it using underscore.js and lodash? Or using the native javascript map and filter functions?
The JSON object
{
"items": [
{
"model": "ooc0d",
"code": "2x4qr",
"price": 33
},
{
"model": "ruie9",
"code": "2f6gi",
"price": 22
},
{
"model": "aqu0d",
"code": "2f6gi",
"price": 21
},
{
"model": "ddebd",
"code": "2f6gi",
"price": 25
},
{
"model": "ddebd",
"code": "2f6gi",
"price": 29
}
],
"models": [
{
"model": "ruie9",
"year": 1998
},
{
"model": "ooc0d",
"year": 1991
},
{
"model": "aqu0d",
"year": 1994
},
{
"model": "ddebd",
"year": 1995
},
{
"model": "odq76",
"year": 1999
}
]
}
My Solution
const { models, items } = jsonData;
const newarray = [];
for(let i = 0; i < models.length; i++) {
for(let j = 0; j < items.length; j++) {
if(items[j].model===models[i].model) {
let obj = {
...items[j],
year: models[i].year
}
newarray.push(obj);
}
}
}

I would take a slightly different approach. I guess you might like it.
const models = [
{
"model": "ruie9",
"year": 1998
},
{
"model": "not-found",
"year": 1991
},
{
"model": "aqu0d",
"year": 1994
},
{
"model": "ddebd",
"year": 1995
},
{
"model": "odq76",
"year": 1999
}
];
const items = [
{
"model": "ooc0d",
"code": "2x4qr",
"price": 33
},
{
"model": "ruie9",
"code": "2f6gi",
"price": 22
},
{
"model": "aqu0d",
"code": "2f6gi",
"price": 21
},
{
"model": "ddebd",
"code": "2f6gi",
"price": 25
},
{
"model": "ddebd",
"code": "2f6gi",
"price": 29
}
];
const transformed = models.reduce((res, val) => {
res[val.model] = val;
return res;
}, {}); // Transform models into a dictionary.
const filtered = items.filter(i => i.model in transformed);
console.log(filtered);

You could do this:
I thought you wanted to add the year from models array too.
If so, look at this implementation. This is more efficient O(n) than O(n*n) solution that you attempted earlier. For large arrays O(n*n) is not preferred.
let items = [{
"model": "ooc0d",
"code": "2x4qr",
"price": 33
},
{
"model": "ruie9",
"code": "2f6gi",
"price": 22
},
{
"model": "aqu0d",
"code": "2f6gi",
"price": 21
},
{
"model": "ddebd",
"code": "2f6gi",
"price": 25
},
{
"model": "ddebd",
"code": "2f6gi",
"price": 29
}
];
let models = [
{
"model": "ruie9",
"year": 1998
},
{
"model": "ooc0d",
"year": 1991
},
{
"model": "aqu0d",
"year": 1994
}
];
let objModels = models.reduce(function(r,v) {
r[v.model] = v;
return r;
}, {});
let objItems = items.reduce(function(r,v) {
r[v.model] = v;
return r;
}, {});
let ans = [];
for(let key in objItems) {
if(key in objModels) {
let o = objItems[key];
o.year = objModels[key].year;
ans.push(o);
}
}
console.log(ans);

You can rewrite
let obj = {
...items[j],
year: models[i].year
}
as
let obj = Object.assign({}, items[j], { year: models[i].year });
And you can also use Array.prototype.forEach instead of a for loop, like so
models.forEach((m) => {
items.forEach((i) => {
if (m.id === i.id) {
let obj = Object.assign({}, i, { year: m.year });
newArray.push(obj);
}
})
})
I tried to keep it as similar to your solution as possible.

Try this snippet:
const jsonData = {
"items": [{
"model": "ooc0d",
"code": "2x4qr",
"price": 33
},
{
"model": "ruie9",
"code": "2f6gi",
"price": 22
},
{
"model": "aqu0d",
"code": "2f6gi",
"price": 21
},
{
"model": "ddebd",
"code": "2f6gi",
"price": 25
},
{
"model": "ddebd",
"code": "2f6gi",
"price": 29
}
],
"models": [{
"model": "ruie9",
"year": 1998
},
{
"model": "ooc0d",
"year": 1991
},
{
"model": "aqu0d",
"year": 1994
},
{
"model": "ddebd",
"year": 1995
},
{
"model": "odq76",
"year": 1999
}
]
};
var newArray = jsonData.models.reduce(
(acc, modelData) => {
let filteredItems = jsonData.items.filter(item => item.model === modelData.model);
if (filteredItems.length) {
acc.push(...filteredItems);
}
return acc;
}, [])
console.log(newArray);

Formatting a JSON data using lodash [duplicate]

This question already has answers here:
How can I access and process nested objects, arrays, or JSON?
(31 answers)
Closed 6 years ago.
I have a JSON data with the following format:
activities
[
{
"id": 32,
"poi_id": 1,
"due_date": "2016-09-08T18:15:00.000Z",
"items": [
{
"id": 21,
"name": "Choluv jar : JAR",
"activity_id": 32
}
]
},
{
"id": 30,
"poi_id": 9,
"due_date": "2016-09-14T18:15:00.000Z",
"items": [
{
"id": 17,
"name": "Bourbon Family : PKT",
"activity_id": 30
},
{
"id": 18,
"name": "Choluv jar : JAR",
"activity_id": 30
}
]
},
{
"id": 29,
"poi_id": 1,
"due_date": "2016-09-27T18:15:00.000Z",
"items": [
{
"id": 16,
"name": "Choluv jar : JAR",
"activity_id": 29
}
]
}
]
I want to reformat this data using lodash or simply javascript to look like this:
/*poi_id is the key*/
"1": [{
"id": 32,
"poi_id": 1,
"due_date": "2016-09-08T18:15:00.000Z",
"items": {
/*due_date is the key*/
"2016-09-08T18:15:00.000Z": [{
"id": 21,
"name": "Choluv jar : JAR",
"activity_id": 32
}]
}
}, {
"id": 29,
"poi_id": 1,
"due_date": "2016-09-27T18:15:00.000Z",
"items": {
"2016-09-27T18:15:00.000Z": [{
"id": 16,
"name": "Choluv jar : JAR",
"activity_id": 29
}]
}
}],
"9": [{
"id": 30,
"poi_id": 9,
"due_date": "2016-09-14T18:15:00.000Z",
"items": {
"2016-09-14T18:15:00.000Z": [{
"id": 17,
"name": "Bourbon Family : PKT",
"activity_id": 30
}, {
"id": 18,
"name": "Choluv jar : JAR",
"activity_id": 30
}]
}
}]
All I want is to put the data that has the same poi_id under one collection with the key of poi_id and same for the items with same due_date.
Here's what I've done so far:
let activityArray = {};
_.forEach(activities, (activityItem) => {
if (!activityArray[activityItem.poi_id]) {
activityArray[activityItem.poi_id] = [];
}
activityArray[activityItem.poi_id].push(activityItem);
_.forEach(activityArray[activityItem.poi_id], (value, key) => {
activityArray[activityItem.poi_id][key].items.unshift(activityArray[activityItem.poi_id][key].due_date);
});
});
And this is what I got:
"1": [{
"id": 32,
"poi_id": 1,
"due_date": "2016-09-08T18:15:00.000Z",
/*unShift added due_date twice here, I want here key value pair*/
"items": [
"2016-09-08T18:15:00.000Z",
"2016-09-08T18:15:00.000Z", {
"id": 21,
"name": "Choluv jar : JAR",
"activity_id": 32
}
]
}, {
"id": 29,
"poi_id": 1,
"due_date": "2016-09-27T18:15:00.000Z",
"items": [
"2016-09-27T18:15:00.000Z", {
"id": 16,
"name": "Choluv jar : JAR",
"activity_id": 29
}
]
}],
"9": [{
"id": 30,
"poi_id": 9,
"due_date": "2016-09-14T18:15:00.000Z",
"items": [
"2016-09-14T18:15:00.000Z", {
"id": 17,
"name": "Bourbon Family : PKT",
"activity_id": 30
}, {
"id": 18,
"name": "Choluv jar : JAR",
"activity_id": 30
}
]
}]
I tried with other approaches too, but couldn't make it like the one I'm expecting.
Please guide me here.
Thanks.

A compact solution in plain Javascript with an object as hash for the items arrays.
var activities = [{ "id": 32, "poi_id": 1, "due_date": "2016-09-08T18:15:00.000Z", "items": [{ "id": 21, "name": "Choluv jar : JAR", "activity_id": 32 }] }, { "id": 30, "poi_id": 9, "due_date": "2016-09-14T18:15:00.000Z", "items": [{ "id": 17, "name": "Bourbon Family : PKT", "activity_id": 30 }, { "id": 18, "name": "Choluv jar : JAR", "activity_id": 30 }] }, { "id": 29, "poi_id": 1, "due_date": "2016-09-27T18:15:00.000Z", "items": [{ "id": 16, "name": "Choluv jar : JAR", "activity_id": 29 }] }],
hash = {},
grouped = {};
activities.forEach(a => {
hash[a.poi_id] = hash[a.poi_id] || {};
hash[a.poi_id][a.due_date] = hash[a.poi_id][a.due_date] || [];
grouped[a.poi_id] = grouped[a.poi_id] || [];
grouped[a.poi_id].push({
id: a.id,
poi_id: a.poi_id,
due_date: a.due_date,
items: { [a.due_date]: hash[a.poi_id][a.due_date] }
});
a.items.forEach(b => hash[a.poi_id][a.due_date].push(b));
});
console.log(grouped);
.as-console-wrapper { max-height: 100% !important; top: 0; }

underscore.js how to combine 2 collections

I have two collections A and B. ( A,B have the exactly same structure, but different nodes values)
now I'd like to add A into B, with exactly the order: A B and without merging or changing any
nodes inside them. ( just like a joint action) { A } + {B}
I've read the documentation for underscore but couldn't find a proper function which gets this job done.
any idea?
==========update with example ========Sample is simplified from a larger structure, if there are errors please let me know=========
var collection1 = [{
"date": "29 January 2014",
"items": [{
"name": "Jack",
"score": 90,
"title": "programmer"
}, {
"name": "TOM",
"score": 52,
"title": "designer"
}]
}, {
"date": "28 January 2014",
"items": [{
"name": "Jim",
"score": 30,
"title": "driver"
}, {
"name": "William",
"score": 52,
"title": "worker"
}]
}]
var collect2 = [{
"date": "26 January 2014",
"items": [{
"name": "Marry",
"score": 92,
"title": "teacher"
}, {
"name": "TOM",
"score": 52,
"title": "designer"
}]
}]
========expected output==============
[{
"date": "29 January 2014",
"items": [{
"name": "Jack",
"score": 90,
"title": "programmer"
}, {
"name": "TOM",
"score": 52,
"title": "designer"
}]
}, {
"date": "28 January 2014",
"items": [{
"name": "Jim",
"score": 30,
"title": "driver"
}, {
"name": "William",
"score": 52,
"title": "worker"
}]
}, {
"date": "26 January 2014",
"items": [{
"name": "Marry",
"score": 92,
"title": "teacher"
}, {
"name": "TOM",
"score": 52,
"title": "designer"
}]
}]

I think what you are looking for is simply Array.concat
var foo = ['a','b','c'];
var bar = ['d','e','f'];
var all = foo.concat(bar); // ['a','b','c','d','e','f'];

Use Underscore#extend as : _.extend(collection1, collection2);
DEMO
col1 = { aa: 'aa', cc: 'cc' }; col2 = { bb: 'bb', dd: 'dd' };
_.extend(col1, col2)
console.log(col1);
# Prints Object {aa: "aa", cc: "cc", bb: "bb", dd: "dd"}