javascript - 减少计数，以便显示每个用户的所有 vendor 的计数

Question

我有一个名为分组的对象:

{ '1':
   [ { id: 1,
       name: 'John Doe',
       supplierName: 'Sup1',
       count: '21' } ],
  '2':
   [ { id: 2,
       name: 'Jane Doe',
       supplierName: 'Sup1',
       count: '95' } ],
  '3':
   [ { id: 3,
       name: 'Paul',
       supplierName: 'Sup1',
       count: '2' },
     { id: 3,
       name: 'Paul',
       supplierName: 'Sup2',
       count: '1' } 
    ] 
}

我用这个创建一个用户对象:

    let users = _.map(grouped, userArray => ({
      id: userArray[0].id,
      name: userArray[0].name,
      suppliers: _.reduce(userArray, (accumulated, supplierObj) => {
        if (supplierObj.supplierName) {
          accumulated.push({
            title: supplierObj.supplierName,
          });
        }
        return accumulated;
      }, []),
    }));

目前看起来像这样:

{
    "users": [
        {
            "id": 1,
            "name": "John Doe",
            "suppliers": [
                {
                    "title": "Sup1"
                }
            ]
        },{
            "id": 2,
            "name": "Jane Doe",
            "suppliers": [
                {
                    "title": "Sup1"
                }
            ]
        },{
            "id": 3,
            "name": "Paul",
            "suppliers": [
                {
                    "title": "Sup1"
                },{
                    "title": "Sup2"
                }
            ]
        }
    ]
}

我现在想添加 count ，我的输出如下所示:

{
    "users": [
        {
            "id": 1,
            "name": "John Doe",
            "count": "21",
            "suppliers": [
                {
                    "title": "Sup1"
                }
            ]
        },{
            "id": 2,
            "name": "Jane Doe",
            "count": "95",
            "suppliers": [
                {
                    "title": "Sup1"
                }
            ]
        },{
            "id": 3,
            "name": "Paul",
            "count": "2",
            "suppliers": [
                {
                    "title": "Sup1"
                },{
                    "title": "Sup2"
                }
            ]
        }
    ]
}

如果我简单地添加 count: userArray[0].count，对于拥有单个 vendor 的每个用户，我的输出都是正确的，但对于拥有多个 vendor 的用户，仅选择第一个。例如。对于上述情况，Paul 将显示计数为 2，对于 Paul，Sup1 有 2 个客户，Sup2 有 1 个客户。我该如何解决这个问题，以便像 Paul 这样拥有多个 vendor 的用户？

Answer 1

  count: userArray.reduce((sum, user) => sum + +user.count, 0)

使用.reduce您可以对计数进行求和。需要一元加号将字符串转换为数字。

而且不需要lodash，如果可以过滤和映射就不需要reduce:

  const users = Object.values(grouped).map(users => ({
     id: users[0].id,
     name: users[0].name,
     suppliers: users.map(user => user.supplierName).filter(it => it),
     count: users.reduce((sum, user) => sum + +user.count, 0),
  }));