over Iterarting Array of object m trying to find if same vendorId of object Adding it average value

Question

 multiple Array of object Like below i have where vendorId is same 
  but i have to find sum of its average value
  var arr=[
 {average:58.5,contractNumber,"5100020753",vendorId:9},
 {average:23.3,contractNumber,"5100020313",vendorId:24},
 {average:58.5,contractNumber,"5100019779",vendorId:9}]

m trying to findout object where vendorId id same adding its averagevalue of object where m facing challenge in iterating the object with similar vendorId

Can someone please explain `where vendorId id same adding its averagevalue of object where m facing challenge in iterating the object with similar vendorId` — brk, Jan 02 '18 at 07:12
@brk create groups based on id and total average for each group — Rajesh, Jan 02 '18 at 07:13
Possible duplicate of [Sum javascript object propertyA values with same object propertyB in array of objects](https://stackoverflow.com/questions/19233283/sum-javascript-object-propertya-values-with-same-object-propertyb-in-array-of-ob) — Rajesh, Jan 02 '18 at 07:14

freelancer · Answer 1 · 2018-01-02T07:21:38.083

0

Do you want something like this

var arr=[{average:58.5,contractNumber:"5100020753",vendorId:9},{average:23.3,contractNumber:"5100020313",vendorId:24},{average:58.5,contractNumber:"5100019779",vendorId:9}];

 var r = {};
 for(let i in arr){
   var e = arr[i];
   if(r[e.vendorId] != undefined){
    r[e.vendorId] += e.average;
   }else{
    r[e.vendorId] = e.average;
   }
 };
 console.log(r);

edited Jan 02 '18 at 07:21

answered Jan 02 '18 at 07:17

freelancer

1,174
5
12

@Rajesh : Thanks for your comment, BTW I changed `.map()` to `for...in` – freelancer Jan 02 '18 at 07:22
can we add key value array of object like [{ "vendoeId":9,"average": 117}] – rohit Jan 02 '18 at 08:07

gurvinder372 · Accepted Answer · 2018-01-02T08:18:09.020

trying to find if same vendorId of object Adding it average value

Use reduce

var sumOfAverage = arr.reduce( ( c, i ) => (
 c[ i.vendorId ] = c[ i.vendorId ] || 0, 
 c[ i.vendorId ] += i.average, 
 c ) , 
{} );

Then you can use map to create the object.

var output = Object.keys( sumOfAverage ).map( s => ({ vendorId : s, average : sumOfAverage[ s ] }) );

Demo

var arr = [{
    average: 58.5,
    contractNumber: "5100020753",
    vendorId: 9
  },
  {
    average: 23.3,
    contractNumber: "5100020313",
    vendorId: 24
  },
  {
    average: 58.5,
    contractNumber: "5100019779",
    vendorId: 9
  }
];

var sumOfAverage = arr.reduce( ( c, i ) => (
     c[ i.vendorId ] = c[ i.vendorId ] || 0, 
     c[ i.vendorId ] += i.average, 
     c ) , 
   {} );

console.log( sumOfAverage );
var output = Object.keys( sumOfAverage ).map( s => ({ vendorId : s, average : sumOfAverage[ s ] }) ); 
console.log( output );

May be he want average based on `vendorId` ie. for `9` and `24` here, your solution is for only `9` — freelancer, Jan 02 '18 at 07:24
@rohit Glad it worked for you. Please also upvote all answers that has helped you so that it also help future visitors. — gurvinder372, Jan 02 '18 at 08:25

over Iterarting Array of object m trying to find if same vendorId of object Adding it average value

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