I am having array of objects that look like this:
const test = {
cat1: {
id: "c1",
name: "category1",
items: [
{
itemName: "item1",
points: 1,
used: true
},
{
itemName: "item2",
points: 3,
used: false
},
{
itemName: "item3",
points: 5,
used: true
}
]
},
cat2: {
id: "c2",
name: "category2",
items: [
{
itemName: "item4",
points: 7,
used: true
},
{
itemName: "item5",
points: 9,
used: false
}
]
},
cat3: {
id: "c3",
name: "category3",
items: [
{
itemName: "item6"
}
]
}
};
I want the output to be an object something like this
{ available: 12 , used: 13}
Need to go over the items array, and derive the available and used based on if used boolean under each object. If its true, add it with used else add it with available entry.Some object may not have points and used , those need to be ignored.
Can someone help with the approach
Code that I tried
const result = Object.values(test).reduce(
(acc, obj) => {
for (let i = 0; i < obj.items.length; i++) {
if (obj.items[i].used) {
return (acc.used = acc.used + obj.items[i].used);
} else acc.available = acc.available + obj.items[i].available;
}
},
{ available: 0, used: 0 }
);
You could flat the arrays and add with the help of an array.
const
test = { cat1: { id: "c1", name: "category1", items: [{ itemName: "item1", points: 1, used: true }, { itemName: "item2", points: 3, used: false }, { itemName: "item3", points: 5, used: true }] }, cat2: { id: "c2", name: "category2", items: [{ itemName: "item4", points: 7, used: true }, { itemName: "item5", points: 9, used: false }] }, cat3: { id: "c3", name: "category3", items: [{ itemName: "item6" }] } },
result = Object
.values(test)
.flatMap(({ items }) => items)
.reduce((r, { points, used }) => {
if (points) r[['available', 'used'][+used]] += points;
return r;
}, { available: 0 , used: 0 });
console.log(result);
2nd request.
const
test = { cat1: { id: "c1", name: "category1", items: [{ itemName: "item1", points: 1, used: true }, { itemName: "item2", points: 3, used: false }, { itemName: "item3", points: 5, used: true }] }, cat2: { id: "c2", name: "category2", items: [{ itemName: "item4", points: 7, used: true }, { itemName: "item5", points: 9, used: false }] }, cat3: { id: "c3", name: "category3", items: [{ itemName: "item6" }] } },
result = Object
.values(test)
.flatMap(({ items }) => items)
.reduce((r, { points = 0, used = false }) => {
r.used += used && points;
r.available += points;
return r;
}, { available: 0 , used: 0 });
console.log(result);
You're returning on the first iteration of the loop. You need to increment acc.used or acc.available in the loop, but only return acc at the end of the loop.
You need to change the parameter of the callback function to curr to match how you use it inside the function.
obj.items[i].used is not a number to add. You should just increment the counter. And there's no obj.items[i].available.
const test = {
cat1: {
id: "c1",
name: "category1",
items: [{
itemName: "item1",
points: 1,
used: true
},
{
itemName: "item2",
points: 3,
used: false
},
{
itemName: "item3",
points: 5,
used: true
}
]
},
cat2: {
id: "c2",
name: "category2",
items: [{
itemName: "item4",
points: 7,
used: true
},
{
itemName: "item5",
points: 9,
used: false
}
]
},
cat3: {
id: "c3",
name: "category3",
items: [{
itemName: "item6"
}]
}
};
const result = Object.values(test).reduce(
(curr, obj) => {
obj.items.forEach(item => {
if (item.used) {
curr.used++;
} else {
curr.available++;
}
});
return curr;
}, {
available: 0,
used: 0
});
console.log(result);
Do first a map() and .flat(), than the .reduce():
const input = { cat1: { id: "c1", name: "category1", items: [ { itemName: "item1", points: 1, used: true }, { itemName: "item2", points: 3, used: false }, { itemName: "item3", points: 5, used: true } ] }, cat2: { id: "c2", name: "category2", items: [ { itemName: "item4", points: 7, used: true }, { itemName: "item5", points: 9, used: false } ] }, cat3: { id: "c3", name: "category3", items: [ { itemName: "item6" } ] } };
const result = Object.values(input).map(obj => obj.items).flat().reduce((acc, obj) => {
if(obj.used) {
acc.used += obj.points;
} else {
acc.available += obj.points || 0;
}
return acc;
}, {available: 0, used: 0})
console.log(result);
Output:
{
"available": 12,
"used": 13
}
UPDATE 1 to get overall points for available:
const input = { cat1: { id: "c1", name: "category1", items: [ { itemName: "item1", points: 1, used: true }, { itemName: "item2", points: 3, used: false }, { itemName: "item3", points: 5, used: true } ] }, cat2: { id: "c2", name: "category2", items: [ { itemName: "item4", points: 7, used: true }, { itemName: "item5", points: 9, used: false } ] }, cat3: { id: "c3", name: "category3", items: [ { itemName: "item6" } ] } };
const result = Object.values(input).map(obj => obj.items).flat().reduce((acc, obj) => {
acc.available += obj.points || 0;
if(obj.used) {
acc.used += obj.points;
}
return acc;
}, {available: 0, used: 0})
console.log(result);
Output:
{
"available": 25,
"used": 13
}
Related
states = [{
name: telangana,
cities: [{
id: 1,
name: foo
}, {
id: 2,
name: joo
}, {
id: 3,
name: goo
}]
},
{
name: punjab,
cities: [{
id: 4,
name: tyu
}, {
id: 5,
name: ery
}, {
id: 6,
name: doo
}]
},
{
name: mumbai,
cities: [{
id: 7,
name: eee
}, {
id: 8,
name: qqq
}, {
id: 9,
name: www
}]
},
]
I want response like [foo, joo, goo, tyu, ery,doo, eee,qqq,www]
Can someone help me ?
Just write one line:
Learn more about reduce() and map()
const states = [{ name: "telangana", cities: [{ id: 1, name: "foo" }, { id: 2, name: "joo" }, { id: 3, name: "goo" }] }, { name: "punjab", cities: [{ id: 4, name: "tyu" }, { id: 5, name: "ery" }, { id: 6, name: "doo" }] }, { name: "mumbai", cities: [{ id: 7, name: "eee" }, { id: 8, name: "qqq" }, { id: 9, name: "www" }] }, ];
const result = states.reduce((acc, { cities }) => [...acc, ...cities.map(({ name }) => name)], []);
console.log(result);
const getNames = (data) => {
const nameArr = [];
data.forEach((ele) => {
ele.cities.forEach((ele2) => {
nameArr.push(ele2.name);
})
})
return nameArr;
}
getNames(states);
Try this please!
states = [{
name: "telangana",
cities: [{
id: 1,
name: "foo"
}, {
id: 2,
name: "joo"
}, {
id: 3,
name: "goo"
}]
},
{
name: "punjab",
cities: [{
id: 4,
name: "tyu"
}, {
id: 5,
name: "ery"
}, {
id: 6,
name: "doo"
}]
},
{
name: "mumbai",
cities: [{
id: 7,
name: "eee"
}, {
id: 8,
name: "qqq"
}, {
id: 9,
name: "www"
}]
},
]
const wantedArray = []
for(i=0; i < states.length; i++){
for(j=0; j < states[i].cities.length; j++){
wantedArray.push(states[i].cities[j].name)
}
}
console.log(wantedArray)
Just give it an empty array, then you loop through the states indexes, each index in states will have a cities array, then you just need to loop it again in that array to get each name of the cities. From then, you are using the push method that Javascript provides to push it to the empty array.
Here's how I'm doing it in JSFiddle, there will have a better way to do this, too.
so I am trying to set up a nested filter on an array of objects.
The thing is that the filter is applied inside the object on a key that is another array of objects.
here is the code:
const items = [
{ name: "123", id: 1, value: true, arr: [{ id: 1 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 2 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 3 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 4 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 5 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 6 }] },
];
const newArray = items.filter((objects) => {
objects.arr.filter((item) => {
if (item.id === 2) {
return objects;
}
});
});
console.log(newArray);
I 'm not sure where to put the return because in this situation i just get an empty array.
You need to check the nested array contains the wanted id and return the result to the filter method.
const
items = [{ name: "123", id: 1, value: true, arr: [{ id: 1 }] }, { name: "456", id: 2, value: false, arr: [{ id: 2 }] }, { name: "456", id: 2, value: false, arr: [{ id: 3 }] }, { name: "456", id: 2, value: false, arr: [{ id: 4 }] }, { name: "456", id: 2, value: false, arr: [{ id: 5 }] }, { name: "456", id: 2, value: false, arr: [{ id: 6 }] }],
result = items.filter(({ arr }) => arr.some(({ id }) => id === 2));
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }
Use Array#some to check if current arr has an element with id equal to 2:
const items = [ { name: "123", id: 1, value: true, arr: [{ id: 1 }] }, { name: "456", id: 2, value: false, arr: [{ id: 2 }] }, { name: "456", id: 2, value: false, arr: [{ id: 3 }] }, { name: "456", id: 2, value: false, arr: [{ id: 4 }] }, { name: "456", id: 2, value: false, arr: [{ id: 5 }] }, { name: "456", id: 2, value: false, arr: [{ id: 6 }] } ];
const newArray = items.filter(({ arr = [] }) =>
arr.some(({ id }) => id === 2)
);
console.log(newArray);
As you contains only one object in arr then you can access this object by using [0] index.
Working Demo :
const items = [
{ name: "123", id: 1, value: true, arr: [{ id: 1 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 2 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 3 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 4 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 5 }] },
{ name: "456", id: 2, value: false, arr: [{ id: 6 }] },
];
const newArray = items.filter((obj) => {
if (obj.arr[0].id === 2) {
return obj;
}
});
console.log(newArray);
I answered you as per the issue you are facing but if you have multiple objects in your arr then you can go ahead with Array.some() method as suggested by other answers.
It's actually about mapping an array of objects and grouping it. Is there any way to convert this array the javascript way without lodash
let fruits = [
{
id: 1,
expired_date: "2021-11-30",
name: "mango"
},
{
id: 2,
expired_date: "2021-11-20",
name: "kiwi"
},
{
id: 3,
expired_date: "2021-11-20",
name: "orange"
},
{
id: 4,
expired_date: "2021-11-10",
name: "banana"
},
{
id: 5,
expired_date: "2021-11-10",
name: "apple"
}
]
grouped to something like this? (grouped by a key in the object, wrapped in an object with 2 keys, one contains the category and the other contains the objects relevant to the group)
let fruits = [
{
expired_date: "2021-11-30",
rows: [
{
id: 1,
expired_date: "2021-11-30",
name: "mango"
}
]
},
{
expired_date: "2021-11-20",
rows: [
{
id: 2,
expired_date: "2021-11-20",
name: "kiwi"
},
{
id: 3,
expired_date: "2021-11-20",
name: "orange"
}
]
},
{
expired_date: "2021-11-10",
rows: [
{
id: 4,
expired_date: "2021-11-10",
name: "banana"
},
{
id: 5,
expired_date: "2021-11-10",
name: "apple"
}
]
}
]
I've read this question but it's not quite the same as expected
Array.reduce should work
const fruits = [ { id: 1, expired_date: "2021-11-30", name: "mango" }, { id: 2, expired_date: "2021-11-20", name: "kiwi" }, { id: 3, expired_date: "2021-11-20", name: "orange" }, { id: 4, expired_date: "2021-11-10", name: "banana" }, { id: 5, expired_date: "2021-11-10", name: "apple" }];
const result = Object.values(fruits.reduce((acc, item) => {
(acc[item.expired_date]??={expired_date: item.expired_date, rows: []}).rows.push(item);
return acc;
}, {}));
console.log(result);
Revised without ??= assignment, it's not supported in IE.
const result = Object.values(fruits.reduce((acc, item) => {
if (acc[item.expired_date]) {
acc[item.expired_date].rows.push(item);
} else {
acc[item.expired_date] = {expired_date: item.expired_date, rows: [item]};
}
return acc;
}, {}));
I have an array of objects here:
const arr = [
{ id: 1, name: "test1", quantity:1 },
{ id: 2, name: "test2", quantity:1 },
{ id: 2, name: "test3", quantity:1 },
{ id: 3, name: "test4", quantity:1 },
{ id: 4, name: "test5", quantity:1 },
{ id: 5, name: "test6", quantity:1 },
{ id: 5, name: "test7", quantity:1 },
{ id: 6, name: "test8", quantity:1 }
];
I want to add quantities of the duplicate objects together before removing them
So the result is:
const arr = [
{ id: 1, name: "test1", quantity:1 },
{ id: 2, name: "test3", quantity:2 },
{ id: 3, name: "test4", quantity:1 },
{ id: 4, name: "test5", quantity:1 },
{ id: 5, name: "test6", quantity:2 },
{ id: 6, name: "test8", quantity:1 }
];
I have seen variations of it done removing duplicates using map or reduce but I haven't seen anything that can what I want to accomplish in an eloquent way without using too many loops.
I have been thinking about how to best accomplish this all day and haven't found anything, any help would be appreciated
You can use reduce with an object to store the element with each id.
const arr = [
{ id: 1, name: "test1", quantity:1 },
{ id: 2, name: "test2", quantity:1 },
{ id: 2, name: "test3", quantity:1 },
{ id: 3, name: "test4", quantity:1 },
{ id: 4, name: "test5", quantity:1 },
{ id: 5, name: "test6", quantity:1 },
{ id: 5, name: "test7", quantity:1 },
{ id: 6, name: "test8", quantity:1 }
];
const res = Object.values(
arr.reduce((acc,curr)=>{
acc[curr.id] = acc[curr.id] || {...curr, quantity: 0};
acc[curr.id].quantity += curr.quantity;
return acc;
}, {})
);
console.log(res);
const arr = [
{ id: 1, name: "test1", quantity: 1 },
{ id: 2, name: "test2", quantity: 1 },
{ id: 2, name: "test3", quantity: 1 },
{ id: 3, name: "test4", quantity: 1 },
{ id: 4, name: "test5", quantity: 1 },
{ id: 5, name: "test6", quantity: 1 },
{ id: 5, name: "test7", quantity: 1 },
{ id: 6, name: "test8", quantity: 1 }
];
var result = arr.reduce(function (r, a) {
r[a.id] = r[a.id] || { id: a.id, quantity: 0, name: a.name };
r[a.id].quantity += a.quantity;
return r;
}, Object.create(null));
console.log(JSON.stringify(result));
Using forEach loop and build object with aggregated quantity count.
const convert = (arr) => {
const res = {};
arr.forEach(({ id, ...rest }) =>
res[id] ? (res[id].quantity += 1) : (res[id] = { id, ...rest })
);
return Object.values(res);
};
const arr = [
{ id: 1, name: "test1", quantity: 1 },
{ id: 2, name: "test2", quantity: 1 },
{ id: 2, name: "test3", quantity: 1 },
{ id: 3, name: "test4", quantity: 1 },
{ id: 4, name: "test5", quantity: 1 },
{ id: 5, name: "test6", quantity: 1 },
{ id: 5, name: "test7", quantity: 1 },
{ id: 6, name: "test8", quantity: 1 },
];
console.log(convert(arr));
I am trying to transform complex JavaScript object. Below is my code. As you can see, it's a lot of code. I am looking for a better/common way to achieve the same result. Maybe ES6 map/Reduce? (I am not allow to do import/require)
function test() {
var input = {
number: 555,
obj1: {
fld1: "11",
persons: [
{
name: "smith",
phone: "222-222-2222"
}
],
},
obj2: {
obj3: {
day: "2019-02-04"
}
},
myArr: [
{
number: 444,
qty: 20,
unit: "ton",
item: {
item_id: 1,
description: "item 1"
}
},
{
number: 111,
qty: 15,
unit: "pieces",
item: {
item_id: 2,
description: "item 2"
}
}
]
}
var result = {
id: input.number,
object1: {
id: input.obj1.number,
contacts: getArr2(input)
},
object2: {
date: input.obj2.obj3.day,
},
list: getArr1(input),
}
return result; // echo back the input received
}
console.log(JSON.stringify(test()));
function getArr1(input) {
var arr = [];
input.myArr.forEach(function (prod) {
let p = {
id: prod.number,
itemId: prod.item.item_id,
description: prod.item.description,
quantity: {
value: prod.qty,
uom: prod.unit
}
}
arr.push(p);
});
return arr;
}
function getArr2(input) {
var arr = [];
input.obj1.persons.forEach(function (person) {
let p = {
name: person.name,
cell: person.phone
}
arr.push(p);
});
return arr;
}
And the result is
{
"id": 555,
"object1": {
"contacts": [{
"name": "smith",
"cell": "222-222-2222"
}]
},
"object2": {
"date": "2019-02-04"
},
"list": [{
"id": 444,
"itemId": 1,
"description": "item 1",
"quantity": {
"value": 20,
"uom": "ton"
}
}, {
"id": 111,
"itemId": 2,
"description": "item 2",
"quantity": {
"value": 15,
"uom": "pieces"
}
}]
}
You could use the power of destructuring and renaming.
function getProds(products) {
return products.map(({ number: id, qty: value, unit: uom, item: { item_id: itemId, description } }) =>
({ id, itemId, description, quantity: { value, uom } }));
}
function getPersons(persons) {
return persons.map(({ name, phone: cell }) => ({ name, cell }));
}
function convert({ number: id, obj1, obj2: { obj3: { day: date } }, myArr }) {
return {
id,
object1: {
id: obj1.number,
contacts: getPersons(obj1.persons)
},
object2: { date },
list: getProds(myArr)
};
}
var data = { number: 555, obj1: { fld1: "11", persons: [{ name: "smith", phone: "222-222-2222" }], }, obj2: { obj3: { day: "2019-02-04" } }, myArr: [{ number: 444, qty: 20, unit: "ton", item: { item_id: 1, description: "item 1" } }, { number: 111, qty: 15, unit: "pieces", item: { item_id: 2, description: "item 2" } }] };
console.log(convert(data));
.as-console-wrapper { max-height: 100% !important; top: 0; }
You're on the right track with map/reduce.
Here's an example (getArr1 would be similar):
function getArr2(input) {
// Don't need map if new object is identical
// Could also do the mapping within the reduce callback
return input.obj1.persons
.map(person => ({ name: person.name, cell: person.phone }))
.reduce((accumulator, currentValue) => {
accumulator.push(currentValue);
return accumulator;
}, []);
}
There's another example in the documentation at: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/reduce#Remove_duplicate_items_in_array