I have an array of objects called employees. I need a solution that will return me a list of groups and respective employees present in the group along with the group properties.
The example is below, I have used an object but the result can also be an array that has a property called groupName within an object. [{groupName:"developer", employees:[],...}..] As long as the response returns a list of groups with their corresponding employees.
Below is the solution I did but I need a solution with a better time complexity that is O(n).
const employees = [
{ "name": "John Doe",
"id": "1",
"groups": [
{ "id": "developerId", "name": "developer", "color": "#fff" },
{ "id": "engineerId", "name": "engineer", "color": "#fff" }
],
"groupId":["developerId", "engineerId"]
},
{ "name": "Jane Doe",
"id": "2",
"groups": [
{ "id": "developerId", "name": "developer", "color": "#fff" },
{ "id": "testerId", "name": "tester", "color": "#fff" }
],
"groupId":["developerId", "testerId"]
}
]
//Solution O(m*n)
let groups = {};
employees.forEach((item) => {
item.groups.forEach((group) => {
if (!groups[group.name]) {
groups[group.name] = {
employees: [item.id],
...group,
};
} else {
groups[group.name].employees = [...groups[group.name].employees, item.id];
}
});
});
//result
{
"developer":{
"id":"developerId",
"employee":[
"1",
"2"
],
"color":"#fff"
},
"engineer":{
"id":"employeeId",
"employee":[
"1",
],
"color":"#fff"
},
"tester":{
"id":"testerId",
"employee":[
"2",
],
"color":"#fff"
}
}
Using Array#reduce and Array#forEach:
const employees = [
{
"name": "John Doe",
"id": "1",
"groups": [
{ "id": "developerId", "name": "developer", "color": "#fff" },
{ "id": "engineerId", "name": "engineer", "color": "#fff" }
],
"groupId": ["developerId", "engineerId"]
},
{
"name": "Jane Doe",
"id": "2",
"groups": [
{ "id": "developerId", "name": "developer", "color": "#fff" },
{ "id": "testerId", "name": "tester", "color": "#fff" }
],
"groupId": ["developerId", "testerId"]
}
];
const groups = employees.reduce((acc, { id: employeeId, groups = [] }) => {
groups.forEach(({ id, name, color }) => {
acc[name] = {
id, color, employee: [...(acc[name]?.employee ?? []), employeeId]
};
});
return acc;
}, {});
console.log(groups);
If you like to add some speed, you could use the old fashioned for statement for iterating, especially of having only a single result object.
This approach does not create an object again and again and uses the already existing objects.
const
employees = [{ name: "John Doe", id: "1", groups: [{ id: "developerId", name: "developer", color: "#fff" }, { id: "engineerId", name: "engineer", color: "#fff" }], groupId: ["developerId", "engineerId"] }, { name: "Jane Doe", id: "2", groups: [{ id: "developerId", name: "developer", color: "#fff" }, { id: "testerId", name: "tester", color: "#fff" }], groupId: ["developerId", "testerId"] }],
result = {};
for (const { id: employeeId, groups } of employees) {
for (const { id, name, color } of groups) {
result[name] ??= { id, color, employee: [] };
result[name].employee.push(employeeId);
}
}
console.log(result);
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Related
I have the following array of objects
{
"nome": "jose",
"categoria": [
{ "id": "1" },
{ "id": "3" },
]
},
{
"nome": "maria",
"categoria": [
{ "id": "2" },
]
},
{
"nome": "pedro",
"categoria": [
{ "id": "1" },
]
}
I have to reorder in another array of categories. Something like this:
{
"id": "1",
"pessoas": [
{
"nome": "jose",
"categoria": [
{ "id": "1" },
{ "id": "3" },
]
},
{
"nome": "pedro",
"categoria": [
{ "id": "1" },
]
},
]
},
{
"id": "2",
"pessoas": [
{
"nome": "maria",
"categoria": [
{ "id": "2" }
]
},
]
},
I have try with the function reduce(), but I couldn't because it is not an object, but a array of objects (categoria)
const group = data.reduce((r, array) => {
r[array.categoria.id] = [...r[array.categoria.id] || [], array];
return r;
}, {});
Someone can help me please?
You could take an object for grouping by id. Inside of reduce, categoria is iterated as well for getting the needed id.
var data = [{ nome: "jose", categoria: [{ id: "1" }, { id: "3" }] }, { nome: "maria", categoria: [{ id: "2" }] }, { nome: "pedro", categoria: [{ id: "1" }] }],
result = Object.values(data.reduce((r, o) => {
o.categoria.forEach(({ id }) => {
if (!r[id]) r[id] = { id, pessoas: [] };
r[id].pessoas.push(o);
});
return r;
}, {}));
console.log(result);
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How do I access the following keys within this array of objects using the 'map' method? I want to access:
'id' inside 'moreInfo'
'fore' inside 'distances'
I get undefined for the following fields when I use
a.map((d) => console.log(d.moreInfo.id));
. I want to use the 'map' method itself so that I can render this content in my React application.
let a = [
{
"Id": "huih23432",
"name": "Kevin",
"dob": "26/06/1995",
"nid": "34535353543",
"images": {
"id": "https://picsum.photos/200",
"nid": "https://picsum.photos/200"
}
},
{
"moreInfo": [
{
"id": "243423423423",
"dob": "16/07/1990",
"name": "JD",
"images": {
"id": "https://picsum.photos/200",
"nid": "https://picsum.photos/200"
},
"distances": {
"fore": "0.91",
"towards": "0.5"
}
}
]
}
];
Try this.
let a = [
{
"Id": "huih23432",
"name": "Kevin",
"dob": "26/06/1995",
"nid": "34535353543",
"images": {
"id": "https://picsum.photos/200",
"nid": "https://picsum.photos/200"
}
},
{
"moreInfo": [
{
"id": "243423423423",
"dob": "16/07/1990",
"name": "JD",
"images": {
"id": "https://picsum.photos/200",
"nid": "https://picsum.photos/200"
},
"distances": {
"fore": "0.91",
"towards": "0.5"
}
}
]
}
];
a.filter(d => d.moreInfo)
.map((d)=>{
const moreInfoObj = d.moreInfo.find(y => y.id);
console.log("'id' inside 'moreInfo': " + moreInfoObj.id);
console.log("'fore' inside 'distances': " + moreInfoObj.distances.fore);
});
Actually you data array of objects and each object has different props. You can use destructuring with default values.
let a = [
{
Id: "huih23432",
name: "Kevin",
dob: "26/06/1995",
nid: "34535353543",
images: {
id: "https://picsum.photos/200",
nid: "https://picsum.photos/200",
},
},
{
moreInfo: [
{
id: "243423423423",
dob: "16/07/1990",
name: "JD",
images: {
id: "https://picsum.photos/200",
nid: "https://picsum.photos/200",
},
distances: {
fore: "0.91",
towards: "0.5",
},
},
],
},
];
a.map(({ moreInfo: [{ id, distances: { fore } = {} }] = [{}] }) =>
console.log({ id, fore })
);
I have the following array
{
"id": "111",
"name": "1111",
"children": [
{
"id": "22222",
"name": "2222",
"children": [
{
"id": "AAAA",
"name": "AAAA",
"children": [
{
"id": "DDD",
"name": "DDD"
},
{
"id": "EEE",
"name": "EEE"
}
]
},
{
"id": "BBBB",
"name": "BBB",
"children": [
{
"id": "FFF",
"name": "FFF"
},
{
"id": "GGG",
"name": "GGG",
"children": [
{
"id": "7777",
"name": "7777"
},
{
"id": "8888",
"name": "8888"
}
]
}
]
}
]
}
]
}
And I would like to create an array with the parents of a child by its ID.
So for example if I wanted to get the path to the child with ID "FFF", then the array would look like something like this:
["1111", "2222", "BBB", "FFF"]
How could I go about doing that?
You could take an iterative and recursive approach.
function getItems({ children, ...object }, key, value) {
var temp;
if (object[key] === value) return [object];
if (children) children.some(o => temp = getItems(o, key, value));
return temp && [object, ...temp];
}
var data = { id: "111", name: "1111", children: [{ id: "22222", name: "2222", children: [{ id: "AAAA", name: "AAAA", children: [{ id: "DDD", name: "DDD" }, { id: "EEE", name: "EEE" }] }, { id: "BBBB", name: "BBB", children: [{ id: "FFF", name: "FFF" }, { id: "GGG", name: "GGG", children: [{ id: "7777", name: "7777" }, { id: "8888", name: "8888" }] }] }] }] };
console.log(getItems(data, 'id', 'FFF'));
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You could implement a recursive search to find all paths and return the correct one when you reach the desired name-value pair.
const isObject = (obj) => obj === Object(obj);
let data = loadData();
let expected = [ '1111', '2222', 'BBB', 'FFF' ];
let actual = findPath(data, 'name', 'FFF');
console.log(JSON.stringify(expected) === JSON.stringify(actual));
function findPath(data, key, value, includeIndicies=false) {
let opts = { found : null, includeIndicies : includeIndicies };
findPathInternal(data, key, value, opts, []);
return opts.found;
}
function findPathInternal(node, key, val, opts, path) {
if (Array.isArray(node)) {
for (let i = 0; i < node.length; i++) {
findPathInternal(node[i], key, val, opts, opts.includeIndicies ? path.concat(i) : path);
}
} else if (isObject(node)) {
if (node[key] === val) {
opts.found = path.concat(val); return; // Exit
} else {
let keys = Object.keys(node);
for (let i = 0; i < keys.length; i++) {
findPathInternal(node[keys[i]], key, val, opts, path.concat(node[key]));
}
}
}
};
function loadData() {
return {
"id": "111",
"name": "1111",
"children": [{
"id": "22222",
"name": "2222",
"children": [{
"id": "AAAA",
"name": "AAAA",
"children": [{
"id": "DDD",
"name": "DDD"
},
{
"id": "EEE",
"name": "EEE"
}
]
},
{
"id": "BBBB",
"name": "BBB",
"children": [{
"id": "FFF",
"name": "FFF"
},
{
"id": "GGG",
"name": "GGG",
"children": [{
"id": "7777",
"name": "7777"
},
{
"id": "8888",
"name": "8888"
}
]
}
]
}
]
}]
};
}
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I am trying filter this array with .filter.
var objList = [
{
"name": "Object0Name",
"id": "Object0ID",
"Object1List": [
{
"id": "Object1id_A1",
"name": "Object1Name_A1",
"Object2List": [
{
"id": 187,
"name": "Object2Name_A1",
"Object3List": [
{
"id": "mammal",
"name": "mammal",
"Object4List": [
{
"id_client": "rabbit",
"Currency": "EUR"
},
{
"id_client": "cat",
"Currency": "EUR",
},
{
"id_client": "tiger",
"Currency": "EUR",
}
]
}
]
}
]
},
{
"id": "Object1id_B1",
"name": "Object1Name_B1",
"Object2List": [
{
"id": 189,
"name": "Object2Name_B1",
"Object3List": [
{
"id": "fish",
"name": "fish",
"Object4List": [
{
"id_client": "tiger shark",
"Currency": "EUR",
},
{
"id_client": "tuna",
"currency": "GBP",
},
]
}
]
}
]
}
]
}
]
var response= objList.filter(function(Object0List){
return Object0List.Object1List.filter(function(Object1List){
return Object1List.Object2List.filter(function(Object2List){
return Object2List.Object3List.filter(function(Object3List){
return Object3List.Object4List.filter(function(Object4List){
return Object4List.id_client==="tiger shark";
});
});
});
});
});
var myJSON = JSON.stringify(response);
console.log('The animal is:');
console.log(myJSON);
But the filter doesn't work. I am receiving all objects. I must receive:
[
{
"name": "Object0Name",
"id": "Object0ID",
"Object1List": [
{
"id": "Object1id_B1",
"name": "Object1Name_B1",
"Object2List": [
{
"id": 189,
"name": "Object2Name_B1",
"Object3List": [
{
"id": "fish",
"name": "fish",
"Object4List": [
{
"id_client": "tiger shark",
"Currency": "EUR",
}
]
}
]
}
]
}
]
}
]
Could someone help me find out what I'm doing wrong? I'm sure the problem is that I'm using the .filter function badly but it took several hours and I'm not capable of fixing it. I think that I do not understand this function for nested objects, I tried to filter the array of nested objects with lambda expressions but I'm also not able.
Thanks you very much.
You could check each property which is an array and take only filtered values.
This approach mutates the original array.
function filter(array, value) {
var temp = array.filter(o =>
Object.keys(o).some(k => {
var t = filter(Array.isArray(o[k]) ? o[k] : [], value);
if (o[k] === value) {
return true;
}
if (t && Array.isArray(t) && t.length) {
o[k] = t;
return true;
}
})
);
if (temp.length) {
return temp;
}
}
var array = [{ name: "Object0Name", id: "Object0ID", Object1List: [{ id: "Object1id_A1", name: "Object1Name_A1", Object2List: [{ id: 187, name: "Object2Name_A1", Object3List: [{ id: "mammal", name: "mammal", Object4List: [{ id: "rabbit", Currency: "EUR" }, { id: "cat", Currency: "EUR" }, { id: "tiger", Currency: "EUR" }] }] }] }, { id: "Object1id_B1", name: "Object1Name_B1", Object2List: [{ id: 189, name: "Object2Name_B1", Object3List: [{ id: "fish", name: "fish", Object4List: [{ id: "tiger shark", Currency: "EUR" }, { id: "tuna", currency: "GBP" }] }] }] }] }],
result = filter(array, 'tiger shark');
console.log(result);
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I assume that every of your objects has this structure:
{
id: "sth",
name: "whatever"
children: [ /***/ ]
}
So then it is quite easy to filter recursively:
function filter(arr, search){
const result = [];
for(const {name, id, children} of arr){
children = filter(children, search);
if(children.length || id === search)
result.push({id, name, children });
}
return result;
}
Usable as:
var response = filter(objList, "tiger shark");
I have below dynamic nested JSON object arrays and I wanted to get the desired output with JavaScript grouped by id from both.
First Array:
[
{
"id": "11",
"name": "emp1",
"location": [
{ "name": "abc", "id": "lc1" }
]
},
{
"id": "11",
"name": "emp2",
"location": [
{ "name": "abc", "id": "lc1" },
]
},
{
"id": "22",
"name": "emp3",
"location": [
{ "name": "xyz", "id": "lc2" }
]
}
]
Second array like below.
[
{
"name": "sub1",
"id": "11"
...
},
{
"name": "sub1.1",
"id": "11"
...
},
{
"name": "sub2",
"id": "22"
...
}
]
Desired Output:
[
{
"id": "11",
"first": [{"name": "emp1"},
{"name": "emp2"}],
"second": [{"name": "sub1"},{"name": "sub1.1"}],
"location": [{"name": "abc"}]
},
{
"id": "22",
"first": [{"name": "emp3"}],
"second": [{"name": "sub2"}],
"location": [{"name": "xyz"}]
}
]
How to get the desired output like above using javascript/angularjs?
I would do it using the amazing Array#reduce function.
Note that I have named your first array as a1, second as a2 and result as res.
a1.reduce(function(arr, obj) {
var existing = arr.filter(function(res) {
return res.id === obj.id
})[0]
if (existing) {
existing.first.push({
name: obj.name
})
} else {
var second = a2.filter(function(res) {
return res.id === obj.id
})
var secondObj = second.length ? second.map(function(sec) {
return {
name: sec.name
};
}) : []
arr.push({
id: obj.id,
first: [{
name: obj.name
}],
second: secondObj,
location: obj.location
})
}
return arr;
}, [])
Here's the working snippet. Take a look!
var a1 = [{
"id": "11",
"name": "emp1",
"location": [{
"name": "abc",
"id": "lc1"
}]
},
{
"id": "11",
"name": "emp2",
"location": [{
"name": "abc",
"id": "lc1"
}]
},
{
"id": "22",
"name": "emp3",
"location": [{
"name": "xyz",
"id": "lc2"
}]
}
]
var a2 = [{
"name": "sub1",
"id": "11"
}, {
"name": "sub1.1",
"id": "11"
},
{
"name": "sub2",
"id": "22"
}
]
var res = a1.reduce(function(arr, obj) {
var existing = arr.filter(function(res) {
return res.id === obj.id
})[0]
if (existing) {
existing.first.push({
name: obj.name
})
} else {
var second = a2.filter(function(res) {
return res.id === obj.id
})
var secondObj = second.length ? second.map(function(sec) {
return {
name: sec.name
};
}) : []
arr.push({
id: obj.id,
first: [{
name: obj.name
}],
second: secondObj,
location: obj.location
})
}
return arr;
}, [])
console.log(res)
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}
var red1 = [{
"id": "11",
"name": "emp1",
"location": [{
"name": "abc",
"id": "lc1"
}]
},
{
"id": "11",
"name": "emp2",
"location": [{
"name": "abc",
"id": "lc1"
}]
},
{
"id": "22",
"name": "emp3",
"location": [{
"name": "xyz",
"id": "lc2"
}]
}
]
var b = [{
"name": "sub1",
"id": "11"
},
{
"name": "sub2",
"id": "22"
}
]
var identication = {}
var result = []
red1.forEach(function(val) {
if (val['id'] in identication) {
var t = {}
t['name'] = val['name']
result[identication[val['id']]]['first'].push(t)
} else {
var t = {}
t['name'] = val['name']
val['first'] = []
val['first'].push(t)
delete val['name']
var identity = result.push(val)
identication[val['id']] = identity - 1;
}
})
b.forEach(function(d) {
if (d['id'] in identication) {
var t = {
'name': d['name']
}
if (!('second' in result[identication[d['id']]])) {
result[identication[d['id']]]['second'] = []
}
result[identication[d['id']]]['second'].push(t)
} else {
var t = {}
for (key in d) {
if (key == 'name')
continue
t[key] = d[key]
}
t['second'] = [{
'name': d['name']
}]
var identity = result.push(t)
identication[d['id']] = identity - 1;
}
})
console.log(result)