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 don't need to map the array, you're really just reducing things inside it.

const totalCostOfAirTickets: data.reduce((prev, next) => prev + next.costOfAirTickets, 0)
const totalCostOfHotel: data.reduce((prev, next) => prev + next.costOfHotel, 0)
const totals = [{totalCostOfAirTickets, totalCostOfHotel}]

In one go, you could do something like

const totals = data.reduce((prev, next) => { 
    prev.costOfAirTickets += next.costOfAirTickets; 
    prev.costOfHotel += next.costOfHotel; 
}, {costOfAirTickets: 0, costOfHotel: 0})

Answer 2

This is the easiest approach I could think off

var data = [{costOfAirtickets: 2500, costOfHotel: 1200},{costOfAirtickets: 1500, costOfHotel: 1000}];
var sum ={};
for(var obj in data){
  for(var ele in data[obj]){
    if(!data[obj].hasOwnProperty(ele)) continue;
      if(sum[ele] === undefined){
        sum[ele] = data[obj][ele];
      }else{
        sum[ele] = sum[ele] + data[obj][ele];
      }
  }

}
var arr = [sum];
console.log(arr);