Aggregate array of object to single distinct value of object javascript

Question

I want to aggregate array of object into single object with each object having distinct value. But My code is not giving me desired output. Can someone please help me?

My Input : 
    [{
        "obj1" : "value1",
        "obj2" : ["abc", "def"],
        "obj3" : ["ghi"],
        "obj4" : "value4",
    },
    {
        "obj1" : "value2",
        "obj2" : ["abc", "mno"],
        "obj3" : ["klm"],
        "obj4" : "value4",
    }]


Output I want:
{
    "obj1" : ["value1","value2"]
    "obj2" : ["abc", "def","mno"],
    "obj3" : ["ghi","klm"],
    "obj4" : ["value4"]
}

My Code:
const result = filterData.reduce((a,c) => 
  (Object.keys(c).map(k => a[k] = [...a[k] || [], c[k]]), a), {})

Answer 1

Here I use some helpers from lodash to solve your problem.

const input = [{
        "obj1" : "value1",
        "obj2" : ["abc", "def"],
        "obj3" : ["ghi"],
        "obj4" : "value4",
    },
    {
        "obj1" : "value2",
        "obj2" : ["abc", "mno"],
        "obj3" : ["klm"],
        "obj4" : "value4",
    }]
    
function customizer(objValue, srcValue) {
  if (_.isArray(objValue)) {
    return _.union(objValue, srcValue);
  }
}
    
const output = input.reduce((acc, cur) => {
  const modifiedCur = _.mapValues(cur, function(o) { return typeof o === 'string' ? [o]: o; }); 
  acc = _.mergeWith(acc, modifiedCur, customizer);
  return acc
},{})    
    
console.log(output)

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js"></script>

Answer 2

You can create a single object from an array of objects using array#reduce. You can get distinct value using Set.

const data = [{ "obj1" : "value1", "obj2" : ["abc", "def"], "obj3" : ["ghi"], "obj4" : "value4", }, { "obj1" : "value2", "obj2" : ["abc", "mno"], "obj3" : ["klm"], "obj4" : "value4", }],
      result = data.reduce((r,o) => {
        Object.keys(o).forEach(k => {
          r[k] = [...new Set((r[k] || []).concat(o[k]))];
        });
        return r;
      },{});
console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }