I have an array I need to merge duplicate values with the sum of amount.
What would be an efficient algorithm
var arr = [{
item: {
id: 1,
name: "Abc"
},
amount: 1
}, {
item: {
id: 1,
name: "Abc"
},
amount: 2
}, {
item: {
id: 2,
name: "Abc"
},
amount: 2
},{
item: {
id: 1,
name: "Abc"
},
amount: 2
}]
I need solution as
[{
item: {
id: 1,
name: "Abc"
},
amount: 5
}, {
item: {
id: 2,
name: "Abc"
},
] amount: 2
}]
simply use Object.values() with Array.reudce() to merge objects and then get the values:
var arr = [{ item: { id: 1, name: "Abc" }, amount: 1 }, { item: { id: 1, name: "Abc" }, amount: 2 }, { item: { id: 2, name: "Abc" }, amount: 2 },{ item: { id: 1, name: "Abc" }, amount: 2 }];
var result = Object.values(arr.reduce((a,curr)=>{
if(!a[curr.item.id])
a[curr.item.id] = Object.assign({},curr); // Object.assign() is used so that the original element(object) is not mutated.
else
a[curr.item.id].amount += curr.amount;
return a;
},{}));
console.log(result);
used map to catch em all :D
var arr = [{ item: { id: 1, name: "Abc" }, amount: 1 }, { item: { id: 1, name: "Abc" }, amount: 2 }, { item: { id: 2, name: "Abc" }, amount: 2 },{ item: { id: 1, name: "Abc" }, amount: 2 }];
var res = {};
arr.map((e) => {
if(!res[e.item.id]) res[e.item.id] = Object.assign({},e); // clone, credits to: #amrender singh
else res[e.item.id].amount += e.amount;
});
console.log(Object.values(res));
Related
How can I get the result from arr1 and arr2, When the ID matches I need to copy the content from arr1
const arr1 = [
{ id: 1, name: "omar" },
{ id: 2, name: "laith" },
{ id: 3, name: "aref" },
]
const arr2 = [
{ id: 1, rating: "good" },
{ id: 2, rating: "very good" },
{ id: 2, rating: "very good" },
{ id: 3, rating: "Excellence" },
{ id: 3, rating: "Excellence" },
]
//expected output
const result = [
{ id: 1, rating: "good", name: "omar" },
{ id: 1, rating: "good", name: "omar" },
{ id: 2, rating: "very good", name: "laith" },
{ id: 3, rating: "Excellence", name: "aref" },
{ id: 3, rating: "Excellence", name: "aref" },
]
use reduce with filter
const arr1 = [ { id: 1, name: "omar" }, { id: 2, name: "laith" }, { id: 3, name: "aref" }, ];
const arr2 = [ { id: 1, rating: "good" }, { id: 2, rating: "very good" }, { id: 2, rating: "very good" }, { id: 3, rating: "Excellence" }, { id: 3, rating: "Excellence" }, ];
const result = arr1.reduce((acc,item) => {
const list = arr2.filter(i => i.id === item.id)
return [...acc, ...list.map(i => ({id: i.id,rating:i.rating, name: item.name}))]
}, [])
console.log(result)
Basically with a loop. Actually 2. Using a temporary object (result) as dictionary (or map) we can make it efficient searching for a match to each id. This is of complexity O(n) basically.
const arr1 = [ { id: 1, name: "omar" }, { id: 2, name: "laith" }, { id: 3, name: "aref" }, ];
const arr2 = [ { id: 1, rating: "good" }, { id: 2, rating: "very good" }, { id: 2, rating: "very good" }, { id: 3, rating: "Excellence" }, { id: 3, rating: "Excellence" }, ];
var result = {}
arr1.forEach(function(item1) {
result[item1.id] = item1;
});
arr2.forEach(function(item2) {
result[item2.id] = (result[item2.id] || item2)
result[item2.id]['rating'] = item2.rating
})
result = Object.values(result)
console.log(result)
I have an array of objects, however i need the array to add a count onto each object, and also remove any duplicates. Is there a simple way to achieve this?
CURRENT
[
{ id: 2, name: 'Adventure' },
{ id: 6, name: 'Crime' },
{ id: 2, name: 'Adventure' },
{ id: 3, name: 'Beautiful' },
{ id: 7, name: 'Drama' },
{ id: 2, name: 'Adventure' }
]
EXPECTED
[
{ id: 2, name: 'Adventure', count: 3 },
{ id: 6, name: 'Crime', count: 1 },
{ id: 3, name: 'Beautiful', count: 1 },
{ id: 7, name: 'Drama', count: 1 }
]
let current = [
{ id: 2, name: 'Adventure' },
{ id: 6, name: 'Crime' },
{ id: 2, name: 'Adventure' },
{ id: 3, name: 'Beautiful' },
{ id: 7, name: 'Drama' },
{ id: 2, name: 'Adventure' }
]
let expected = current.reduce((acc, cur) => {
let curFind = acc.find(item => item.id === cur.id)
if (curFind) {
curFind.count++
return acc
} else {
return [...acc, {
...cur,
count: 1
}]
}
}, [])
console.log('expected:', expected)
I'm populing a pdf template with an array of employees, and now I need to count the number of employees working in a same department, I found a way to count the total of concurrences but I can't enumarate the employee working in the department and the total of them. Can you help me? Thanks!!!
For example, I have this array of objects
const employees = [
{
id: 1,
name: "john",
department: {
id: 1,
},
},
{
id: 1,
name: "Mike",
department: {
id: 3,
},
},
{
id: 1,
name: "Leona",
department: {
id: 1,
},
},
{
id: 1,
name: "Lara",
department: {
id: 1,
},
},
];
Result Expected:
const employees = [
{
id: 1,
name: "john",
department: {
id: 1,
},
totalForDeparments: "1/3",
},
{
id: 1,
name: "Mike",
department: {
id: 3,
},
totalForDeparments: "1/1",
},
{
id: 1,
name: "Leona",
department: {
id: 1,
},
totalForDeparments: "2/3",
},
{
id: 1,
name: "Lara",
department: {
id: 1,
},
totalForDeparments: "3/3",
},
];
First you group by the department.id - then you can iterate the original array adding the correct indexes.
const employees = [{id:1,name:"john",department:{id:1}},{id:1,name:"Mike",department:{id:3}},{id:1,name:"Leona",department:{id:1}},{id:1,name:"Lara",department:{id:1}},];
var grouped = employees.reduce(function(agg, item) {
agg[item.department.id] = agg[item.department.id] || {
count: 0,
current: 0
}
agg[item.department.id].count++;
return agg;
}, {});
employees.map(function(item) {
var data = grouped[item.department.id]
data.current++;
item.totalForDeparments = data.current + "/" + data.count
})
console.log(employees)
.as-console-wrapper {max-height: 100% !important}
I'm trying to find an element on a multidimentionnal array usin JAVASCRIPT function, but I get error
This is my array's data:
export const datas = [
{
id: 1,
firstName: 'John',
tables: [
{ ID: 11, title: 'Lorem' },
{ ID: 12, title: 'Ipsum' },
],
},
{
id: 2,
firstName: 'Doe',
tables: [
{
ID: 22,
title: 'Arke',
nodes: [{ name: 'Name1' }, { name: 'Name2' }, { name: 'Name3' }],
},
{ ID: 23, title: 'Korem' },
],
},
{
id: 3,
firstName: 'Brad',
tables: [
{
ID: 30,
title: 'Mern',
nodes: [{ name: 'Name4' }, { name: 'Name5' }, { name: 'Name6' }],
},
{
ID: 31,
title: 'Full',
nodes: [{ name: 'Name7' }, { name: 'Name8' }, { name: 'Name9' }],
},
],
},
];
I've tried a reccursive function but it's not work, this is my code :
export const findById = (arr, id) => {
for (let o of arr) {
if (o.tables.length > 0) {
let a = findById(o.tables.nodes, 'id');
console.log(a);
}
}
};
I want to print the Object with ID 22, the problem is that I don't have the same structure in each dimension, and it still confuse me..
My Input : 22
My output :
{
ID: 22,
title: 'Arke',
nodes: [{ name: 'Name1' }, { name: 'Name2' }, { name: 'Name3' }],
},
Have you an idea how to edit my function to get my input's response ?
Your recursive function wasn't too far off, you need to check if the item as a tables first before recursively calling it again. And then finally just check the ID in the loop.
eg..
const datas=[{id:1,firstName:"John",tables:[{ID:11,title:"Lorem"},{ID:12,title:"Ipsum"}]},{id:2,firstName:"Doe",tables:[{ID:22,title:"Arke",nodes:[{name:"Name1"},{name:"Name2"},{name:"Name3"}]},{ID:23,title:"Korem"}]},{id:3,firstName:"Brad",tables:[{ID:30,title:"Mern",nodes:[{name:"Name4"},{name:"Name5"},{name:"Name6"}]},{ID:31,title:"Full",nodes:[{name:"Name7"},{name:"Name8"},{name:"Name9"}]}]}];
function findById(arr, ID) {
for (const a of arr) {
if (a.tables) {
const r = findById(a.tables, ID);
if (r) return r;
}
if (a.ID === ID) return a;
}
}
console.log(findById(datas, 22));
if you just need the nested data you can use flatMap and find
const findById = (arr, id) =>
arr
.flatMap(d => d.tables)
.find(t => t.ID === id)
const datas = [{
id: 1,
firstName: 'John',
tables: [{
ID: 11,
title: 'Lorem'
},
{
ID: 12,
title: 'Ipsum'
},
],
},
{
id: 2,
firstName: 'Doe',
tables: [{
ID: 22,
title: 'Arke',
nodes: [{
name: 'Name1'
}, {
name: 'Name2'
}, {
name: 'Name3'
}],
},
{
ID: 23,
title: 'Korem'
},
],
},
{
id: 3,
firstName: 'Brad',
tables: [{
ID: 30,
title: 'Mern',
nodes: [{
name: 'Name4'
}, {
name: 'Name5'
}, {
name: 'Name6'
}],
},
{
ID: 31,
title: 'Full',
nodes: [{
name: 'Name7'
}, {
name: 'Name8'
}, {
name: 'Name9'
}],
},
],
},
];
console.log(findById(datas, 22))
js has amazing array options https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
the ones which will help you most are probably:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/flatMap
here are some examples
// get the base with id 22
const baseWith22ID = datas.filter(f => f.tables.filter(s => s.id = 22))
// (i guess you want this one) get all elements with id 22
const onlyElementsWith22ID = datas.flatMap(f => f.tables.filter(s => s.id = 22))
I'm trying to get an array of names of objects that have options.amount all equals to zero. Thanks for your time. This is what i tryed:
let variants = [
{
name: 'extra',
options: [
{
name: 'meat',
price: 3,
amount: 0
},
{
name: 'cheese',
price: 1,
amount: 0
}
]
},
{
name: 'sauce',
options: [
{
name: 'ketchup',
price: 2,
amount: 1
},
{
name: 'mayo',
price: 1,
amount: 0
}
]
}
];
//Expected output = ['extra']
let arrayOfOptionsNames = variants.map(x => x.options.filter(y => y.amount === 0 ? x.name : 0))
console.log(arrayOfOptionsNames)
You could use Array.prototype.filter() and Array.prototype.every() method to get your result. Every method test if every elements of the array pass the test by the given callback function and returns a boolean value.
const variants = [
{
name: 'extra',
options: [
{
name: 'meat',
price: 3,
amount: 0,
},
{
name: 'cheese',
price: 1,
amount: 0,
},
],
},
{
name: 'sauce',
options: [
{
name: 'ketchup',
price: 2,
amount: 1,
},
{
name: 'mayo',
price: 1,
amount: 0,
},
],
},
];
const ret = variants
.filter((x) => x.options.every((y) => y.amount === 0))
.map((x) => x.name);
console.log(ret);
You could filter and get the wanted property.
let variants = [{ name: 'extra', options: [{ name: 'meat', price: 3, amount: 0 }, { name: 'cheese', price: 1, amount: 0 }] }, { name: 'sauce', options: [{ name: 'ketchup', price: 2, amount: 1 }, { name: 'mayo', price: 1, amount: 0 }] }],
result = variants
.filter(({ options }) => options.every(({ amount }) => !amount))
.map(({ name }) => name);
console.log(result);