Group objects in an array by Id - JavaScript

Question

I have an object array that has two fields id, and the type of action permission

const array=[
{view: false, id: 1},
{create: false, id: 1},
{read: false, id: 1},
{update: false, id: 1},
{delete: false, id: 1},
{view: false, id: 2},
{create: false, id: 2},
{read: false, id: 2},
{update: false, id: 2},
{delete: false, id: 2},
]

I want to convert this in to the following array:

const permissions=[
{
id: 1,
view: false,
read: false,
create: false,
delete:false,
update:false
},
{
id: 2,
view: false,
read: false,
create: false,
delete:false,
update:false
}
]

Answer 1

You can iterate over the array using Array#reduce while updating a Map where the id is the key and its resulting object is the value.

In the end, you would have the grouped objects per id as the values in this map:

const array = [
  {view: false, id: 1},
  {create: false, id: 1},
  {read: false, id: 1},
  {update: false, id: 1},
  {delete: false, id: 1},
  {view: false, id: 2},
  {create: false, id: 2},
  {read: false, id: 2},
  {update: false, id: 2},
  {delete: false, id: 2},
];

const res = [...
  array.reduce((map, { id, ...elem }) =>
    map.set(id, { ...(map.get(id) || { id }), ...elem })
  , new Map)
  .values()
];

console.log(res);