Is there a shorter way to merge duplicated objects

Question

I was curious if there was a shorter way to accomplish this?

Check if there are duplicates by matching certain properties then push the duplicated array.items into the original array.items

var array = [
    {type: "Fruit", something: "abc", more: "properties", items: [{word:"Apple", abc: "ok"}]},
    {type: "Fruit", something: "abc", more: "properties", items: [{word:"Orange", abc: "ok"}]}
];

merge(array) would become

array = [
    {type: "Fruit", something: "abc", more: "properties", items:[{word:"Apple", abc: "ok"}, {word:"Orange", abc: "ok"}]}
];

     merge: function(arr) {
        var rec, dupeIndices, foundDupes;
        for (var idx = 0, len = arr.length; idx < len - 1; ++idx) {
            rec = arr[idx];
            if (rec === null) continue;
            dupeIndices = findDupeIndices(rec, arr.slice(idx + 1), idx + 1);
            if (dupeIndices.length === 0) continue;
            foundDupes = true;
            processDupes(rec, dupeIndices, arr);
        }
        if (foundDupes) cleanUp(arr);
    },
    cleanUp: function(arr) {
        for (var idx = 0; idx < arr.length; ++idx) {
            if (arr[idx] === null) arr.splice(idx--, 1);
        }
    },
    processDupes: function(rec, dupeIndices, arr) {
        var dupeRealIdx, dupeRec;
        for (var dupeIdx = 0, dupesLen = dupeIndices.length; dupeIdx < dupesLen; ++dupeIdx) {
            dupeRealIdx = dupeIndices[dupeIdx];
            dupeRec = arr[dupeRealIdx];
            updateRecord(rec, dupeRec);
            arr[dupeRealIdx] = null;
        }
    },
    findDupeIndices: function(rec, arr, offset) {
        var other, result = [];
        for (var idx = 0, len = arr.length; idx < len; ++idx) {
            other = arr[idx];
            if (other === null) continue;
            if (isDupe(rec, other)) result.push(idx + offset);
        }
        return result;
    },
    isDupe: function(a, b) {
        return (a.type === b.type && a.something === b.something);
    },
    updateRecord: function(rec, dupe) {
        for (var i = 0; i < dupe.items.length; i++) {
            rec.items.push(dupe.items[i]);
        }
    }

http://stackoverflow.com/questions/30025965/merge-duplicate-objects-in-array-of-objects — Ivan Barayev, Aug 26 '16 at 23:59
I edited because your data structures were not formatted as code and thus not very readable. If you want to edit some more to clear things up further, you can do that yourself with the 'edit' link. — jfriend00, Aug 27 '16 at 02:26

Aikon Mogwai · Answer 1 · 2016-08-27T02:01:26.507

1

Do you need to remove duplicates?

var arr = [
    {type: "Fruit", items:[{word:"Apple"}]}, 
    {type: "Fruit", items:[{word:"Orange"}]}
];

var obj = arr.reduce(function(obj, i) {
    obj[i.type] = [].concat(obj[i.type] || [], i.items); return obj;    
}, {});

var res = [];
for (var key in obj)
    res.push({type: key, items: obj[key]});
    // or to unique items
    // res.push({type: key, items: obj[key].filter(function (e, i, r) { return r.indexOf(e) == i})}); 

console.log(res);

edited Aug 27 '16 at 02:01

answered Aug 27 '16 at 01:56

Aikon Mogwai

4,954
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Yes I would need to remove duplicates also I would need to match with multiple properties. – Houla Banada Aug 27 '16 at 03:09

score 1 · Accepted Answer · answered Aug 27 '16 at 04:15

You can use an object to help sort, here im sorting on the type and combining the items

 var obj = [
    {type: "Fruit", something: "abc", more: "properties", items: [{word:"Apple", abc: "ok"}]},
    {type: "Fruit", something: "abc", more: "properties", items: [{word:"Orange", abc: "ok"}]}
];

var sorted = {};
obj.forEach(function(element){
  if(sorted[element.type]){
    sorted[element.type].items.push.apply(sorted[element.type].items,element.items)
  }else{
    sorted[element.type] = {
      type: element.type,
      something: element.something,
      more: element.more,
      items:element.items
    }
  }

});

var sortedarray = Object.keys(sorted).map(function(item){
return sorted[item]});

console.log(sortedarray);

working example : http://codepen.io/nilestanner/pen/NAkZbz

I used push.apply because I was merging two arrays. In your example object Items was an array, so this way all items of the object are added — Niles Tanner, Aug 27 '16 at 05:40

Is there a shorter way to merge duplicated objects

2 Answers2