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I have an array of objects and inside the array there is another array of objects, I would like to sum the values. So the sum is based on the same picker_id. Then sum current_capacity, process_time_in_minutes, and picked_qty inside products which is array of objects.
Here is my data:
var arr = [
{
current_capacity: 6000,
picker_id: "icQrHPuE2fMZslceSG6liwuRar92",
process_time_in_minutes: 10,
products: [
{
product_id: 1,
picked_qty: 2
},
{
product_id: 2,
picked_qty: 3
}
]
},
{
current_capacity: 2500,
picker_id: "icQrHPuE2fMZslceSG6liwuRar92",
process_time_in_minutes: 20,
products: [
{
product_id: 1,
picked_qty: 10
}
]
},
{
current_capacity: 36000,
picker_id: "WIRzfIZALeftRk3DRGvh4nBdxQV2",
process_time_in_minutes: 15,
products: [
{
product_id: 1,
picked_qty: 2
},
{
product_id: 2,
picked_qty: 3
}
]
}
];
Here is my code:
var res = arr.reduce((acc, obj) => {
var existObj = acc.find((item) => item.picker_id === obj.picker_id);
if (existObj) {
let total_picked = obj.products.reduce((acc2, curr) => acc2 + curr);
// console.log("total_picked", total_picked);
existObj.current_capacity =
existObj.current_capacity + obj.current_capacity;
existObj.process_time_in_minutes =
existObj.process_time_in_minutes + obj.process_time_in_minutes;
existObj.total = existObj.total ? existObj.total : 0 + total_picked;
return acc;
}
acc.push(obj);
return acc;
}, []);
const formatted = res.map((el) => {
return {
picker_id: el.picker_id,
total_volume: el.current_capacity,
total_time: el.process_time_in_minutes,
total_products: el.total
};
});
The result is as below:
[
{
picker_id: "icQrHPuE2fMZslceSG6liwuRar92"
total_volume: 8500
total_time: 30
total_products: "0[object Object]"
},
{
picker_id: "WIRzfIZALeftRk3DRGvh4nBdxQV2"
total_volume: 36000
total_time: 15
total_products: undefined
}
]
Expected like below:
[
{
picker_id: "icQrHPuE2fMZslceSG6liwuRar92"
total_volume: 8500
total_time: 30
total_products: 15
},
{
picker_id: "WIRzfIZALeftRk3DRGvh4nBdxQV2"
total_volume: 36000
total_time: 15
total_products: 5
}
]
Using a little parameter destructuring, I think you can do a little further clean-up after you fix the problems others have described. My version might look like this:
const extract = (xs) => Object .values (xs .reduce (
(acc, {current_capacity, picker_id, process_time_in_minutes, products}) => {
const curr = acc [picker_id] || (acc [picker_id] = {
picker_id, total_volume: 0, total_time: 0, total_products: 0
})
curr .total_volume += current_capacity
curr .total_time += process_time_in_minutes
curr .total_products += products .reduce ((t, p) => t + p .picked_qty, 0)
return acc
},
{}
))
const arr = [{current_capacity: 6e3, picker_id: "icQrHPuE2fMZslceSG6liwuRar92", process_time_in_minutes: 10, products: [{product_id: 1, picked_qty: 2}, {product_id: 2, picked_qty: 3}]}, {current_capacity: 2500, picker_id: "icQrHPuE2fMZslceSG6liwuRar92", process_time_in_minutes: 20, products: [{product_id: 1, picked_qty: 10}]}, {current_capacity: 36e3, picker_id: "WIRzfIZALeftRk3DRGvh4nBdxQV2", process_time_in_minutes: 15, products: [{product_id: 1, picked_qty: 2}, {product_id: 2, picked_qty: 3}]}]
console .log (extract (arr))
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You can also achieve your output by this
function getProductQty(arr){
let total = 0;
arr.forEach(prd => {
total += prd.picked_qty
})
return total;
}
const result = arr.reduce((acc,product) => {
if(!acc.hasOwnProperty(product.picker_id)){
acc[product.picker_id] = {
picker_id: product.picker_id,
total_volume: product.current_capacity,
total_time: product.process_time_in_minutes
}
acc[product.picker_id].total_products = getProductQty(product.products);
}else{
acc[product.picker_id].total_volume = acc[product.picker_id].total_volume + product.current_capacity
acc[product.picker_id].total_time = acc[product.picker_id].total_time + product.process_time_in_minutes
acc[product.picker_id].total_products = acc[product.picker_id].total_products + getProductQty(product.products);
}
return acc
},{})
console.log(Object.values(result),'result');
Issue with your implementation was if the existObj doesn't exit in your acc, you were directly pushing the obj instead you need to process the total first from the inner array of products.
I have updated your code to look cleaner and maintainable.
Approach:
build a dict for each picker_id which hold the computed data
convert dict to list
var result = arr.reduce((acc, obj) => {
if (!acc[obj.picker_id]) {
acc[obj.picker_id] = {
total_volume: 0,
total_time: 0,
total_products: 0
};
}
const selectedPicker = acc[obj.picker_id];
const total_picked = obj.products.reduce((acc2, item) => acc2 + item.picked_qty, 0);
selectedPicker.total_volume = selectedPicker.total_volume + obj.current_capacity;
selectedPicker.total_time =
selectedPicker.total_time + obj.process_time_in_minutes;
selectedPicker.total_products = selectedPicker.total_products + total_picked;
return acc;
}, {});
const formatted = Object.keys(result).reduce((acc, picker_id) => {
acc.push({
picker_id,
...result[picker_id]
})
return acc;
}, [])
console.log("formmated", formatted);
I'm trying to sum the values of arrays inside an array.
const arr = [
{ key: 0, x: [4,5,6], y: [1,2,3,4]},
{ key: 0, x: [1], y: [] }
]
The expected output would be 26 ( 4 + 5 + 6 + 1 + 2 ...)
No idea how to do this, tried with reduce but I don't know how to access the other array.
Any help would be great.
You can try getting the sum of nested object's array first, then sum them up and return like the following way:
const arr = [
{ key: 0, x: [4,5,6], y: [1,2,3,4]},
{ key: 0, x: [1], y: [] }
]
const sum = arr.reduce((a, c) => {
const cTemp = Object.values(c).flat().reduce((aa,cc) => aa+cc, 0);;
return a + cTemp;
}, 0);
console.log(sum);
const total = [
{key: 0, x: [4, 5, 6], y: [1, 2, 3, 4]},
{key: 0, x: [1], y: []},
]
.map(({x, y}) => [...x, ...y])
.reduce((total, curr) => total + curr.reduce((a, b) => a + b), 0);
const total = [
{key: 0, x: [4, 5, 6], y: [1, 2, 3, 4]},
{key: 0, x: [1], y: []},
]
.map(({x, y}) => [...x, ...y])
.reduce((total, curr) => total + curr.reduce((a, b) => a + b), 0);
console.log(total);
No idea how to do this, tried with reduce but I don't know how to
access the other array.
You can create another function named sum to sum all values in an array. After that, at each object, you can use Spread ... to merge 2 arrays into one like this.
const arr = [ { key: 0, x: [4,5,6], y: [1,2,3,4]},
{ key: 0, x: [1], y: [] }];
const sum = (arr) => arr.reduce((acc, curr) => acc+= curr, 0);
const result = arr.reduce((acc, {x, y}) => acc += sum([...x, ...y]), 0);
console.log(result);
Another way is to use Array#flatMap to get all values, then use Array#reduce to sum them.
const allValues = arr.flatMap(({x, y}) => [...x, ...y]);
const result = allValues.reduce((acc, curr) => acc+= curr, 0);
const arr = [ { key: 0, x: [4,5,6], y: [1,2,3,4]},
{ key: 0, x: [1], y: [] }];
const allValues = arr.flatMap(({x, y}) => [...x, ...y]);
const result = allValues.reduce((acc, curr) => acc+= curr, 0);
console.log(result);
The flatMap() method returns a new array formed by applying a given
callback function to each element of the array, and then flattening
the result by one level
This works for me.
const arr = [{
key: 0,
x: [4, 5, 6],
y: [1, 2, 3, 4]
},
{
key: 0,
x: [1],
y: []
}
]
var total = 0;
arr.forEach(function(value) {
value.x.forEach(function(x) {
total += x;
});
value.y.forEach(function(y) {
total += y;
});
});
console.log(total);
I have a nested object look like this:
let obj = {
F:{
asian: {
"35-44": 1,
"55-": 1,
},
"asian/black": {
"0-24": 1,
"35-44": 1,
"45-54": 2,
},
},
M:{
asian: {
"35-44": 1,
"55-": 1,
},
white: {
"0-24": 1,
"35-44": 1,
"45-54": 2,
},
},
}
And I want to flatten the object to this:
res = {
F: 6,
M: 6,
asian: 4,
"asian/black": 4,
white: 4,
"0-24": 2,
"35-44": 4,
"45-54": 4,
"55-": 2,
}
That every value in res should be the sum of the deepest object values(F, M) and object values with the same key(0-24, 35-44...). I feel this can be done using recursion and just can't get it right. The code I write:
let returnVal = 0
const flatten = (obj, prefix = '', res = {}) => {
return Object.entries(obj).reduce((r, [key, val]) => {
if(typeof val === 'object'){
flatten(val, key, r)
} else {
res[key] = val
returnVal = val;
}
if (key in res) {
res[key] += returnVal
} else {
res[key] = 0
res[key] += returnVal
}
return r
}, res)
}
console.log(flatten(obj))
it will output:
result = {
"0-24": 2,
"35-44": 2,
"45-54": 4,
"55-": 2,
F: 2,
M: 2,
asian: 2,
"asian/black": 2,
white: 2,
}
F, M, and some other keys are not correct. Thanks!
Another, perhaps simpler, approach is as follows:
const consolidate = (obj, path = [], results = {}) =>
Object .entries (obj) .reduce ((results, [k, v]) =>
Object (v) === v
? consolidate (v, [...path, k], results)
: [...path, k] .reduce (
(results, n) => ({...results, [n] : (results[n] || 0) + v}),
results
),
results)
const data = {F: {asian: {"35-44": 1, "55-": 1}, "asian/black": {"0-24": 1, "35-44": 1, "45-54": 2}}, M: {asian: {"35-44": 1, "55-": 1}, white: {"0-24": 1, "35-44": 1, "45-54": 2}}}
console .log (consolidate (data))
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We recursively track paths taken through the object, such as ['F', 'asian/black', '45-54'] or ['M', 'white'] or simply ['f'] as well as an object containing the final results. When we the value at the current node is an object, we recur, adding the current property name to the path. When it's not (for this data it must therefore hit a number), we hit a base case in which we take each node in the current path, and update the results object by adding that number to the value for the node in the results object, or setting it to the current value if that value doesn't exist.
There is a potential issue with the default parameters, as described in another Q & A. If someone tried to map the consolidate function directly over an array of input objects, it would fail. If this is a concern, it's easy enough to swap the default parameters for a wrapper function:
const _consolidate = (obj, path, results) =>
Object .entries (obj) .reduce ((results, [k, v]) =>
Object (v) === v
? _consolidate (v, [...path, k], results)
: [...path, k] .reduce (
(results, n) => ({...results, [n] : (results[n] || 0) + v}),
results
),
results)
const consolidate = (obj) =>
_consolidate (obj, [], {})
const data = {
F: {
asian: {
"35-44": 1,
"55-": 1,
},
"asian/black": {
"0-24": 1,
"35-44": 1,
"45-54": 2,
},
},
M: {
asian: {
"35-44": 1,
"55-": 1,
},
white: {
"0-24": 1,
"35-44": 1,
"45-54": 2,
},
},
};
const isObject = obj => Object.prototype.toString.call(obj) === "[object Object]";
function nestKeys(obj, parent = "") {
return Object.keys(obj).map(key => {
const k = parent.length ? [parent, key].join(".") : key;
if (!isObject(obj[key])) {
return k;
}
return nestKeys(obj[key], k);
}).flat();
}
function flatObj(obj) {
const map = {};
const keys = nestKeys(obj);
keys.forEach(nestedKey => {
const splited = nestedKey.split(".");
const val = splited.reduce((acc, cur) => acc[cur], obj);
splited.forEach(k => {
map[k] = (map[k] || 0) + val;
})
});
return map;
}
console.log(flatObj(data));
I'm stuck again with some flattening and renaming of the following.
What I got:
test = [
{
date: '2020-03-30',
station: {
id: 0,
name: 'some description'
},
firstValues: [
{
result: 1,
type: 4,
max: 18,
min: 1,
},
{
result: 2,
type: 5,
max: 15,
min: 2,
}
],
lastValues: [
{
result: 1,
type: 3,
max: 17,
min: 1
},
{
result: 2,
type: 8,
max: 20,
min: 2
}
],
iD: 'xxx3',
count: 1
},
{
next object with same structure
}
]
What I try to achieve:
test = [
{
date: '2020-03-30',
station: 'some description',
first_E01_result: 1,
first_E01_type: 4,
first_E01_max: 18,
first_E01_min: 1,
first_E02_result: 2,
first_E02_type: 5,
first_E02_max: 15,
first_E02_min: 2,
last_E01_result: 1,
last_E01_type: 3,
last_E01_max: 17,
last_E01_min: 1,
last_E02_result: 2,
last_E02_type: 8,
last_E02_max: 20,
last_E02_min: 2,
iD: 'xxx3',
count: 1
},
{
next object with same structure
}
]
I'm quite aware that my approach isn't the right thing. I tried different things so far but couldn't get it working. I'm totally stuck again to find the right way because I do run into two main issues:
How can I make the difference between first and last values? (switch case or if and if else?)
and
How can I access the name property from the station object and assign it to the key of "station"
Here is my last approach which is still missing the right code for the mentioned problems:
convertTest(input) {
return input.map(obj => {
const obj1 = {};
const obj2 = {};
for (const prop in obj) {
if (obj.hasOwnProperty(prop) && Array.isArray(obj[prop])) {
for (let i = 0; i < obj[prop].length; i++) {
for (const [key, value] of Object.entries(obj[prop][i])) {
const name = 'first_EO' + (i + 1).toString() + '_' + key;
obj2[name] = value;
}
}
} else {
obj1[prop] = obj[prop];
}
const dataconverted = Object.assign({}, obj1, obj2);
return dataconverted;
}
});
}
You could take a recursive approach for all other nested objects except the first level with special cases.
var data = [{ date: '2020-03-30', station: { id: 0, name: 'some description' }, firstValues: [{ result: 1, type: 4, max: 18, min: 1 }, { result: 2, type: 5, max: 15, min: 2 }], lastValues: [{ result: 1, type: 3, max: 17, min: 1 }, { result: 2, type: 8, max: 20, min: 2 }], iD: 'xxx3', count: 1 }],
getPath = object => Object.entries(object).reduce((r, [k, v], i) => {
if (v && typeof v === 'object') {
r.push(...getPath(v).map(([left, right]) => [(Array.isArray(object) ? 'E' + (i + 1).toString().padStart(2, 0) : k) + '_' + left, right]));
} else {
r.push([k, v]);
}
return r;
}, []),
result = data.map(o => Object.fromEntries(Object.entries(o).reduce((r, [k, v]) => {
if (k === 'station') {
r.push([k, v.name]);
} else if (v && typeof v === 'object') {
if (k.endsWith('Values')) k = k.slice(0, -6);
r.push(...getPath(v).map(([left, right]) => [k + '_' + left, right]));
} else {
r.push([k, v]);
}
return r
}, [])));
console.log(result);
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You should use Map and Object.keys
var test = [{"date":"2020-03-30","station":{"id":0,"name":"some description"},"firstValues":[{"result":1,"type":4,"max":18,"min":1},{"result":2,"type":5,"max":15,"min":2}],"lastValues":[{"result":1,"type":3,"max":17,"min":1},{"result":2,"type":8,"max":20,"min":2}],"iD":"xxx3","count":1}]
console.log(flatten(test));
function flatten(arr) {
return arr.map(el => ModifyObject(el))
}
function ModifyObject(el) {
const obj = {};
obj.date = el.date;
obj.iD = el.iD;
obj.count = el.count;
obj.station = el.station.name;
flattenObjectByProperty(obj, el, 'firstValues')
flattenObjectByProperty(obj, el, 'lastValues')
return obj;
}
function flattenObjectByProperty(obj, el, property) {
(el[property] || []).map((child, i) => {
Object.keys(child).forEach(key => {
obj[property + '_E' + i + '_' + key] = child[key]
});
});
}
Please try this.
test = test.map((elem) => {
elem.firstValues.forEach((child, index) => {
for(let key in child){
let v = `first_E${index+1}_${key}`
elem[v] = child[key];
}
})
elem.lastValues.forEach((child, index) => {
for(let key in child){
let v = `last_E${index+1}_${key}`
elem[v] = child[key];
}
})
elem['station'] = elem.station.name;
delete elem.firstValues;
delete elem.lastValues;
return elem;
})
You can use Array.prototype.reduce to flatten as per your requirement
const test = [
{
date: '2020-03-30',
station: {
id: 0,
name: 'some description'
},
firstValues: [
{
result: 1,
type: 4,
max: 18,
min: 1,
},
{
result: 2,
type: 5,
max: 15,
min: 2,
}
],
lastValues: [
{
result: 1,
type: 3,
max: 17,
min: 1
},
{
result: 2,
type: 8,
max: 20,
min: 2
}
],
iD: 'xxx3',
count: 1
}
];
const result = test.reduce((acc, curr) => {
const { firstValues, lastValues, ...rest } = curr;
const modifiedFirstValues = firstValues.reduce((r, c, i) => {
Object.entries(c).forEach(([key, value]) => {
const modifiedKey = `first_E${i + 1}_${key}`;
r[modifiedKey] = value;
});
return r;
}, Object.create(null));
const modifiedLastValues = lastValues.reduce((r, c, i) => {
Object.entries(c).forEach(([key, value]) => {
const modifiedKey = `last_E${i + 1}_${key}`;
r[modifiedKey] = value;
});
return r;
}, Object.create(null));
const finalObj = {
...rest,
...modifiedFirstValues,
...modifiedLastValues
};
acc.push(finalObj);
return acc;
}, []);
console.log(result);
im trying to add counting number for duplicate in JS.
and i am completely stack in this case below.
i need to compare objects with two value (x, y) and if there are same values of (x, y) add count 1 on new objects.
is there any way to convert data to newData such as below?
const data = [
{id: 1, x: 1, y: 1},
{id: 2, x: 2, y: 2},
{id: 3, x: 1, y: 1},
]
const newData = [
{x: 1, y:1 ,count:2}
{x: 2, y:2 ,count:1}
]
use .reduce() function
const data = [
{id: 1, x: 1, y: 1},
{id: 2, x: 2, y: 2},
{id: 3, x: 1, y: 1},
]
const output = data.reduce((acc, curr) => {
curr.count = 1;
const exists = acc.find(o => o.x === curr.x && o.y === curr.y);
exists ? exists.count++ : acc.push(({ x, y, count } = curr));
return acc;
}, []);
console.log(output);
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One way of doing so, is to create a map with the x and y values, and increment the count accordingly, then convert the map into an array:
const data = [
{id: 1, x: 1, y: 1},
{id: 2, x: 2, y: 2},
{id: 3, x: 1, y: 1},
]
const makeXYMap = (data) => data.reduce((acc, cur) => {
const { x, y } = cur;
const entry = acc[`${x}_${y}`];
if (entry) {
acc[`${x}_${y}`] = {...entry, count: entry.count + 1};
} else {
acc[`${x}_${y}`] = { x, y, count: 1 };
}
return acc;
}, {});
const makeArray = (XYMap) => Object.values(XYMap);
console.log(makeArray(makeXYMap(data)));
Note that complexity wise, this solution is a O(N).
https://jsfiddle.net/9o35neg7/
const data = [
{ id: 1, x: 1, y: 1 },
{ id: 2, x: 2, y: 2 },
{ id: 3, x: 1, y: 1 },
// .. so on ..
];
const countedData = data.reduce((acc, { x, y }, index, array) => {
acc[`x${x}y${y}`] = {
x,
y,
count: (acc[`x${x}y${y}`] ? acc[`x${x}y${y}`].count : 0) + 1
};
return index === (array.length - 1) ? Object.values(acc) : acc;
}, {});
console.log(countedData);
Use forEach and build an object with key (made of x, y) and values (aggregate count). Get the Object.values to get the results as array.
const data = [
{id: 1, x: 1, y: 1},
{id: 2, x: 2, y: 2},
{id: 3, x: 1, y: 1},
]
const counts = (arr, res = {}) => {
arr.forEach(({x , y}) =>
res[`${x}-${y}`] = { x, y, count: (res[`${x}-${y}`]?.count ?? 0) + 1 })
return Object.values(res);
}
console.log(counts(data))