CODEWITHSUNDEEP
javascriptarrays
Hannan
Hannan

Reputation: 1191

Javascript combining two objects into new object with unique data element i.e. year

I have following two objects in JS where year is unique in both objects. I want to combine them into a new object where the year is same.

var financials = [{"year": 2013, "rev_prod1": 10000, "rev_prod2": 5000}, {"year": 2014, "rev_prod1": 8000, "rev_prod2": 10000}, {"year": 2015, "rev_prod1": 15000, "rev_prod2": 20000}]

var stats = [{"year": 2013, "units_sold": 900, "hours": 55},{"year": 2014, "units_sold": 800, "hours": 45}, {"year": 2015, "units_sold": 1000, "hours": 70}]

The expected output will look like this:

var combinedData = [{"year": 2013, "rev_prod1": 10000, "rev_prod2": 5000, "units_sold": 900, "hours": 55}, {"year": 2014, "rev_prod1": 8000, "rev_prod2": 10000, "units_sold": 800, "hours": 45}, {"year": 2015, "rev_prod1": 15000, "rev_prod2": 20000, "units_sold": 1000, "hours": 70}]

Upvotes: 2

Views: 62

Answers (3)

user7626079
user7626079

Reputation:

I've wrote a function to grouping 2 list with common property, is that what you want?

function commonProps(list1, list2, common) {
    var output = [], commons = {}, combined = list1.concat(list2)
    for(var i in combined){
        var item = combined[i], $index
        if(commons[item[common]] != null){
            $index = commons[item[common]]
            for(var j in item){
                output[$index][j] = item[j]
            }
        } else {
            commons[item[common]] = output.push(item) -1
        }
    }

    return output
}

Upvotes: 1

Nina Scholz
Nina Scholz

Reputation: 386746

You could use a hash table for the stats objects and merge the values by iterating the keys.

var financials = [{ "year": 2013, "rev_prod1": 10000, "rev_prod2": 5000 }, { "year": 2014, "rev_prod1": 8000, "rev_prod2": 10000 }, { "year": 2015, "rev_prod1": 15000, "rev_prod2": 20000 }],
    stats = [{ "year": 2013, "units_sold": 900, "hours": 55 }, { "year": 2014, "units_sold": 800, "hours": 45 }, { "year": 2015, "units_sold": 1000, "hours": 70 }],
    hash = Object.create(null);

stats.forEach(function (o) {
    hash[o.year] = o;
});

financials.forEach(function (o) {
    Object.keys(hash[o.year]).forEach(function (k) {
        o[k] = hash[o.year][k];
    });
});

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

ES6 with Map and Object.assign.

var financials = [{ "year": 2013, "rev_prod1": 10000, "rev_prod2": 5000 }, { "year": 2014, "rev_prod1": 8000, "rev_prod2": 10000 }, { "year": 2015, "rev_prod1": 15000, "rev_prod2": 20000 }],
    stats = [{ "year": 2013, "units_sold": 900, "hours": 55 }, { "year": 2014, "units_sold": 800, "hours": 45 }, { "year": 2015, "units_sold": 1000, "hours": 70 }],
    map = new Map(stats.map(o => [o.year, o]));

financials.forEach(o => Object.assign(o, map.get(o.year)));

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

Upvotes: 1

kukkuz
kukkuz

Reputation: 42370

You can first create a hashtable by merging similar objects using #forEach() and then extract the required array using a #map() function - see demo below:

var financials = [{"year": 2013, "rev_prod1": 10000, "rev_prod2": 5000}, {"year": 2014, "rev_prod1": 8000, "rev_prod2": 10000}, {"year": 2015, "rev_prod1": 15000, "rev_prod2": 20000}];
var stats = [{"year": 2013, "units_sold": 900, "hours": 55},{"year": 2014, "units_sold": 800, "hours": 45}, {"year": 2015, "units_sold": 1000, "hours": 70}]
var hash = {};

// function to create a hashtable
function classify(e) {
   if(hash[e.year]) {
     Object.keys(e).forEach(function(c){
        hash[e.year][c] = e[c];
     });
   } else {
     hash[e.year] = e;
   }
}

// add to hash
financials.forEach(classify);
stats.forEach(classify);

// extract the result
var result = Object.keys(hash).map(function(e){
  return hash[e];
});

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

Upvotes: 1

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