Combine Array of Objects With Similar Keys Conditionally Using JavaScript

Combine Array of Objects with similar keys conditionally using JavaScript

You can use Array.prototype.reduce to aggregate the data by day and Object.keys with Array.prototype.map to format it to the desired output:

const data=[{day:'monday',time:'10:00 AM',type:'start',unit:1},{day:'monday',time:'11:30 AM',type:'end',unit:1},{day:'tuesday',time:'01:00 PM',type:'start',unit:1},{day:'tuesday',time:'06:00 PM',type:'end',unit:1},{day:'wednesday',time:'10:00 AM',type:'start',unit:1},{day:'wednesday',time:'06:00 PM',type:'end',unit:1}];

const grouped = data.reduce((all, {day, time, type, unit}) => {
  if (!all.hasOwnProperty(day)) all[day] = { day, unit };
  all[day][`${type}_time`] = time;
  return all;
}, {});
const result = Object.keys(grouped).map((a,i) => ({sr_no: i + 1, ...grouped[a]}));
console.log(result);

Javascript: Merge Two Arrays of Objects, Only If Not Duplicate (Based on Specified Object Key)

You can create a set of IDs from initialData and this will make "check if ID is already in initial data" faster - O(1):

var initialData = [{    'ID': 1,    'FirstName': 'Sally'  },  {    'ID': 2,    'FirstName': 'Jim'  },  {    'ID': 3,    'FirstName': 'Bob'  }];
var newData = [{    'ID': 2,    'FirstName': 'Jim'  },  {    'ID': 4,    'FirstName': 'Tom'  },  {    'ID': 5,    'FirstName': 'George'  }];
var ids = new Set(initialData.map(d => d.ID));var merged = [...initialData, ...newData.filter(d => !ids.has(d.ID))];
console.log(merged);

Conditionally merge array of objects

You can do it with reduce

const arrayToBeCompacted = [
  {
    section: "Section name 1",
    path: ["segment1", "segment2"],
    ids: ["id1"]
  },
  {
    section: "Section name 1",
    path: ["segment1", "segment2"],
    ids: ["id2"]
  },
  {
    section: "Section name2",
    path: ["segment1", "segment2"],
    ids: ["id3"]
  },
  {
    section: "Another section",
    path: ["segment1", "segment2"],
    ids: ["id4"]
  },
  {
    section: "Another section",
    path: ["segment1", "segment2"],
    ids: ["id5"]
  },
]

const compacted = Object.values(arrayToBeCompacted.reduce((res, {section, path, ids}) => {
  const key = section + path.join('|')
  const existing = res[key] || {ids: [], section, path}
  existing.ids = [...existing.ids, ...ids]
  res[key] = existing
  return res

}, {}))

console.log(compacted)

Combine array of string and number as object array conditionally

Try this vanilla js solution as well using filter, Object.values and map

var output = count.map((s, i) => ({
  [fruits[i]]: s
})).filter(s => Object.values(s)[0]);

Demo

var fruits = [  "Apple",  "Banana",  "Apricot",  "Bilberry"];
var count = [3, 5, 0, 2];
var output = count.map((s, i) => ({  [fruits[i]]: s})).filter(s => Object.values(s)[0]);
console.log(output);

Merge objects with the same id in an array by adding their numeric properties

You can use a combination of higher-level built-in functions like Object.keys, Array#reduce, and Array#map to conditionally combine array entries when certain properties match.

var array = [{  Username: 'user1',  Balance: '123'}, {  Username: 'user2',  Balance: '213'}, {  Username: 'user1',  Balance: '424'}]
var map = array.reduce(function (map, e) {  map[e.Username] = +e.Balance + (map[e.Username] || 0)   return map}, {})
var result = Object.keys(map).map(function (k) {  return { Username: k, Balance: map[k] }})
console.log(result)

How to combine array of objects into one object and then create another object within that array based on a condition on the index

Please note, that your required output is IMPOSSIBLE - but if there's more than one object with the same key, the output could have an array of values for that key - see code

If each group of items in the original array begins with an object with a single key "Battery" - then this will perform the majicks for you

const arrayOfObjects = [{"Battery": "Battery"},{"batteryDetailsKey": ["Serial Number","Type","Part Number",]},{"batteryDetailsVal": ["HJ3CA19347410218LJ98 100 QC","Extended Range","4P94-Q001",]},{"Modules": "Modules"},{"moduleDetailsKey": ["Serial Number","Part Number","Cell Count",]},{"moduleDetailsVal": ["83675327350061093222581609899001","LJ98-10C779-A01","32",]},{"assetSeparator": "assetSeparator"},{"Battery": "Battery"},{"batteryDetailsKey": ["Serial Number","Type","Part Number"]},{"batteryDetailsVal": ["HJ3CA19347410218LJ98 101 QC","Extended Range","4P94-Q002"]},{"Modules": "Modules"},{"moduleDetailsKey": ["Serial Number","Part Number","Cell Count"]},{"moduleDetailsVal": ["83675327350061093222581609899002","LJ98-10C779-A02","28"]},{"moduleDetailsVal": ["83675327350061093222581609899003","LJ98-10C779-A03","27"]},{"assetSeparator": "assetSeparator"},{"Battery": "Battery"},{"batteryDetailsKey": ["Serial Number","Type","Part Number",]},{"batteryDetailsVal": ["HJ3CA19347410218LJ98 102 QC","Extended Range","4P94-Q003",]},{"Modules": "Modules"},{"moduleDetailsKey": ["Serial Number","Part Number","Cell Count",]},{"moduleDetailsVal": ["83675327350061093222581609899004","LJ98-10C779-A01","32",]}];

const shapeIWantArrayOfObjects = [];
let currentOutput;
for (let object of arrayOfObjects) {
    if (Object.keys(object).join('') === 'Battery') {
        currentOutput = {};
        shapeIWantArrayOfObjects.push(currentOutput);
    }
    Object.entries(object).forEach(([key, val]) => {
        const existing = currentOutput[key];
        if (!existing) {
            currentOutput[key] = val;
        } else {
            if (!Array.isArray(currentOutput[key][0])) {
                currentOutput[key] = [currentOutput[key]];
            }
            currentOutput[key].push(val);
        }
    });
}
console.log(shapeIWantArrayOfObjects);

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How to merge array of keys and arrays of values into an object?

use this one.

var a = ["F", "M"];
var b = ["female", "male"];
var c = ["fa-female", "fa-male"];

var resultArray = [];
for(var i = 0; i < a.length; i++) {
    resultArray [a[i]] = [b[i], c[i]];
}

Combine Array of Objects With Similar Keys Conditionally Using JavaScript