I have JSON like this:
[
{
platformId: 1,
payout: 15,
numOfPeople: 4
},
{
platformId: 1,
payout: 12,
numOfPeople: 3
},
{
platformId: 2,
payout: 6,
numOfPeople: 5
},
{
platformId: 2,
payout: 10,
numOfPeople: 1
},
]
And I want to Group it by platformId
with sum of payout
and numOfPeople
.
I.e. in result I want JSON like this:
[
"1": {
payout: 27,
numOfPeople: 7
},
"2": {
payout: 16,
numOfPeople: 6
}
]
I tried to use underscore.js
's _.groupBy
method, and it groups fine, but how I can get the SUM of objects properties values like I demonstrated above?
You can do this without Underscore:
var result = data.reduce(function(acc, x) {
var id = acc[x.platformId]
if (id) {
id.payout += x.payout
id.numOfPeople += x.numOfPeople
} else {
acc[x.platformId] = x
delete x.platformId
}
return acc
},{})
But why would you want an object with numeric keys? You could convert it back to a collection:
var toCollection = function(obj) {
return Object.keys(obj)
.sort(function(x, y){return +x - +y})
.map(function(k){return obj[k]})
}
toCollection(result)
Note that objects are mutated, so you may to clone them first if you want to maintain the original data.