How to get distinct values from an array of objects in JavaScript?

Question

Assuming I have the following:

var array = 
    [
        {\"name\":\"Joe\", \"age\":17}, 
        {\"name\":\"Bob\", \"age\":17}, 
        {\"name\":\"Carl\         


        

Answer 1

Just found this and I thought it's useful

_.map(_.indexBy(records, '_id'), function(obj){return obj})

Again using underscore, so if you have an object like this

var records = [{_id:1,name:'one', _id:2,name:'two', _id:1,name:'one'}]

it will give you the unique objects only.

What happens here is that indexBy returns a map like this

{ 1:{_id:1,name:'one'}, 2:{_id:2,name:'two'} }

and just because it's a map, all keys are unique.

Then I'm just mapping this list back to array.

In case you need only the distinct values

_.map(_.indexBy(records, '_id'), function(obj,key){return key})

Keep in mind that the key is returned as a string so, if you need integers instead, you should do

_.map(_.indexBy(records, '_id'), function(obj,key){return parseInt(key)})