Combining JavaScript objects in an array with same key value

Question

I have been trying to combine objects inside an array with same id-value. The array that I have is like this:

[
{\"id\" : \"abcd\",\"val1\" : 1,\"val2\": 1,          


        

Answer 1

The standard way to do that is to use an object as map (here b) :

var b = {}, arr = [];
for (var id in a) {
  var oa = a[id], ob = b[oa.id];
  if (!ob) arr.push(ob = b[oa.id] = {}); 
  for (var k in oa) ob[k] = k==='id' ? oa.id : (ob[k]||0)+oa[k];
}
console.log(arr)