合并数组中相同id 的数量

 
问题

let badge = [{id: 323, badge: 10},{id: 323, badge: 10},{id: 311, badge: 1},{id: 311, badge: 1},{id: 311, badge: 1},{id: 311, badge: 1},{id: 352, badge: 3},{id: 352, badge: 100},{id: 480, badge: 5}]

目标

let badgeMerge = [{id: 323, badge: 20},{id: 311, badge: 4},{id: 352, badge: 103},{id: 480, badge: 5}]

第一种方式

let keys = Array.from(new Set(badge.map(item => item.id)))
  var badgeMerge = keys.map(key => {
    return {
      id: key,
      badge: badge.filter(item => item.id == key).reduce((pre, cur) => pre+cur.badge, 0)
    }
  })

第二种方式

Object.values(badge.reduce((t,c)=>{
    (!t[c.id] && (t[c.id]= c)) || (t[c.id] && (t[c.id].badge += c.badge));
    return t;
}, {}));