Reduce to sum all the values ​​in the array of the object failed

Question

As a result, I got it [object Object]9778177, I tried to parse this value, but nothing helps, something is wrong.

let x = [{
  "total_count": 7
}, {
  "total_count": 9
}, {
  "total_count": 778
}, {
  "total_count": 177
}]

let sum = x.reduce((accum, obj) => {
   return accum + obj.total_count
})

console.log(sum)

Answer 1

You can add an initial value because the first iteration starts with the object for the battery and there you do not have the property you will need.

let sum = x.reduce((accum, obj) => accum + obj.total_count, 0);