我需要合并对象。 它们都有相同的键，但数值不同。 我需要获取每个键的值之和

Question

New to JS and programming in general. I've tried numerous solutions on SO and other resources and cannot seem to figure this out. I have twenty or more objects representing user 'votes'. The all have the same keys and different values depending on the user input. I need to 'tally the votes' by summing the different values and return a single object.

Example:

{
  "Seattle" : "1",
  "Chicago" : "2",
  "New York" : "3"
}

{
  "Chicago" : "1",
  "New York" : "2",
  "Seattle" : "3"
}

{
  "New York" : "1",
  "Chicago" : "2",
  "Seattle" : "3"
}

I'd like the three objects above to be distilled to this:

{
  "New York" : "6",
  "Seattle" : "7",
  "Chicago" : "5"
}

If you could point me in the right direction I'd greatly appreciate it!

Answer 1

Assuming your votes are in an array, you can reduce it into a single object:

 const votes = [ { "Seattle" : "1", "Chicago" : "2", "New York" : "3" }, { "Chicago" : "1", "New York" : "2", "Seattle" : "3" }, { "New York" : "1", "Chicago" : "2", "Seattle" : "3" } ]; const tally = votes.reduce((a, e) => { for (const p in e) { a[p] = a[p] + (+e[p]) || +e[p]; } return a; }, {}) console.log(tally); 

Answer 2

Another option with reduce/keys/map which somewhat more functional looking:

 const objs = [{ "Seattle": "1", "Chicago": "2", "New York": "3" }, { "Chicago": "1", "New York": "2", "Seattle": "3" }, { "New York": "1", "Chicago": "2", "Seattle": "3" } ] var result = objs.reduce((r, c) => Object.keys(r).map((x) => r[x] = +r[x] + (+c[x])) && r) console.log(result)