Merge Objects: Problem with comparing and merge two objects in javascript

Question

Good night. Some charitable soul to help me with a problem about javascript objects. Thank you very much who can ...

var arrA = [
    {language:'php', count_access:5},
    {language:'c', count_access:7}
];

var arrB = [
    {language:'php', count_access:0},
    {language:'c', count_access:0},
    {language:'python', count_access:0},
    {language:'ace', count_access:0},
    {language:'electron', count_access:0},
];

var result = [...arrA, ...arrB].reduce((acc, item) => { 
    return item;
 }) ;

arrA.concat(result)

//How would you do for the output to be

/*[
{language:'php', count_access:5},
{language:'c', count_access:7},
{language:'python', count_access:0},
{language:'ace', count_access:0},
{language:'electron', count_access:0},
]*/

I'd use reduce like `let result = [...arrA, ...arrB].reduce((acc, item) => { code here }, [])` ... that should be enough to get you to write something for yourself — Bravo, Oct 29 '19 at 01:55
var arrA = [ {nome:'php', count:5}, {nome:'c', count:7} ]; var arrB = [ {nome:'php', count:0}, {nome:'c', count:0}, {nome:'python', count:0}, ]; var result = [...arrA, ...arrB].reduce((acc, item) => { return item; }, []) ; arrA.concat(result) — Taffarel Xavier, Oct 29 '19 at 02:00
For example: var arrA = [ {nome:'php', count:5}, {nome:'c', count:7} ]; var arrB = [ {nome:'php', count:0}, {nome:'c', count:0}, {nome:'python', count:0}, {nome:'ace', count:0}, {nome:'electron', count:0}, ]; var result = [...arrA, ...arrB].reduce((acc, item) => { return item; }) ; arrA.concat(result) — Taffarel Xavier, Oct 29 '19 at 02:05
that only works because that code returns `{nome:'python', count:0}` ... but it that's a coincidence — Bravo, Oct 29 '19 at 02:06
Do you need to increase the count? Or are you just trying to merge the objects? Your example doesn't really show what you need... — Bruno Monteiro, Oct 29 '19 at 02:08
Sorry. I need to merge equal to the output I put, in edition... — Taffarel Xavier, Oct 29 '19 at 02:09
https://stackoverflow.com/questions/171251/how-can-i-merge-properties-of-two-javascript-objects-dynamically — Bruno Monteiro, Oct 29 '19 at 02:10

score 2 · Accepted Answer · edited Oct 29 '19 at 02:37

This will work, it also adds up the counts for matching language

var arrA = [
    {language:'php', count:5},
    {language:'c', count:7}
];

var arrB = [
    {language:'php', count:0},
    {language:'c', count:0},
    {language:'python', count:0},
    {language:'ace', count:0},
    {language:'electron', count:0},
];

let result = [...arrA, ...arrB].reduce((acc, item) => {
  let found = acc.find(x => x.language=== item.language);
  if (found) {
    found.count += item.count;
  } else {
    acc.push(Object.assign({},item));
  }
  return acc;
}, [])
console.log(result);

Merge Objects: Problem with comparing and merge two objects in javascript

1 Answers1