Get unique items from array of objects

Question

i have an array

friendList = [
              {id: 1, fName: 'Sam', lName: 'Brian', profilePic: 'sam.jpg'},
              {id: 2, fName: 'Dam', lName: 'Nary', profilePic: 'dam.jpg'},
              {id: 3, fName: 'Jam', lName: 'kent', profilePic: 'jam.jpg'},
              {id: 1, fName: 'Sam', lName: 'Brian', profilePic: 'sam.jpg'},
              {id: 3, fName: 'Jam', lName: 'kent', profilePic: 'jam.jpg'}, 
             ]

how can i get a unique array of this friendList.. such that the result is :

friendList = [
              {id: 1, fName: 'Sam', lName: 'Brian', profilePic: 'sam.jpg'},
              {id: 2, fName: 'Dam', lName: 'Nary', profilePic: 'dam.jpg'},
              {id: 3, fName: 'Jam', lName: 'kent', profilePic: 'jam.jpg'}
             ]

[No, they are not](https://stackoverflow.com/questions/18773778/create-array-of-unique-objects-by-property). — Daedalus, Jun 03 '20 at 08:37
var uniqueArry = Object.values(friendList.reduce((acc,ele)=>{return {...acc,...{[ele.id]:ele}}},{})) — Ajai, Jun 03 '20 at 09:05

score 0 · Accepted Answer · answered Jun 03 '20 at 09:38

If your friendList items should be filtered by unique id property, you can make use of the fact that object should have unique keys.

With that in mind, you may

traverse your source array using Array.prototype.reduce() and build up an object, having id as a key and corresponding item object as a value
extract Object.values() into array of unique records

Following is a proof of a concept live-demo:

const friendList = [{id:1,fName:'Sam',lName:'Brian',profilePic:'sam.jpg'},{id:2,fName:'Dam',lName:'Nary',profilePic:'dam.jpg'},{id:3,fName:'Jam',lName:'kent',profilePic:'jam.jpg'},{id:1,fName:'Sam',lName:'Brian',profilePic:'sam.jpg'},{id:3,fName:'Jam',lName:'kent',profilePic:'jam.jpg'},],
             
      friendListMap = friendList.reduce((r,item) => 
        (r[item.id] = item, r), {}),
        
      dedupeFriendList = Object.values(friendListMap)
      
console.log(dedupeFriendList)

.as-console-wrapper{min-height:100%;}

Get unique items from array of objects

1 Answers1