Get the addition of a property in an array of objects with repeated IDs in Javascript-CodePudding

I have and array of objects, something like that:

myArr = [{id: 1, x:100, y:200},{id:1, x:50, y:25},{id:2, x:60, y:80},{id:2, x:50, y:100},{id:2, x:50, y:60}]

What I want is to make an array like that:

wantedArray = [{id: 1, x: 150, y: 225}, {id:2, x: 160, 240}]

Where make the addition of each x, y if "id" is the same. Thanks!

CodePudding user response：

You can use array#reduce to sum on property x and y for each unique id in an object accumulator.

const myArr = [{id: 1, x:100, y:200},{id:1, x:50, y:25},{id:2, x:60, y:80},{id:2, x:50, y:100},{id:2, x:50, y:60}],
      result = Object.values(myArr.reduce((r, {id, x, y}) => {
        r[id] = r[id] || {id, x: 0, y: 0};
        r[id].x  = x;
        r[id].y  = y;
        return r;
      },{}));
console.log(result);

CodePudding user response：

You do not need to reduce Object.values

This works too and saves a casting

const myArr = [{id: 1, x:100, y:200},{id:1, x:50, y:25},{id:2, x:60, y:80},{id:2, x:50, y:100},{id:2, x:50, y:60}]

const sum = myArr.reduce((acc,cur) => {
  const obj = acc.find(({id}) => id===cur.id);
  if (obj) { obj.x =cur.x; obj.y =cur.y }
  else acc.push(cur)
  return acc;
},[]);
console.log(sum)