Sum all data in array of objects into new array of objects

Question

I have an array of objects that looks like this:

var data = [{costOfAirtickets: 2500, costOfHotel: 1200},{costOfAirtickets: 1500, costOfHotel: 1000}]
         


        

Answer 1

You could reduce the array by taking an object for summing.

var data = [{ costOfAirtickets: 2500, costOfHotel: 1200 }, { costOfAirtickets: 1500, costOfHotel: 1000 }],
    keys = ['costOfAirtickets', 'costOfHotel'],
    sum = data.reduce((r, o) => {
        keys.forEach(k => r[k] += o[k]);
        return r;
    }, Object.assign(...keys.map(k => ({ [k]: 0 }))));

console.log(sum);