如何获取数组中的重复对象？

Question

我有一个这样的数组：

    var clients=[{"id":1,"name":"john","age":20},
{"id":3,"name":"dean","age":23},
{"id":12,"name":"harry","age":14},
{"id":1,"name":"sam","age":22},
{"id":13,"name":"Bolivia","age":16},
{"id":7,"name":"sabi","age":60},
{"id":7,"name":"sahra","age":40},
{"id":4,"name":"natie","age":53},{"id":7,"name":"many","age":22}]

我想找到重复的对象并像这样对它们进行聚类：

 [
       {
       "id":1,
        "clients":[
                    {"id":1,"name":"john","age":20},
                    {"id":1,"name":"sam","age":22}
                   ]
       },
     {
       "id":7,
       "clients":[
                   {"id":7,"name":"sabi","age":60},
                   {"id":7,"name":"sahra","age":40},
                   {"id":7,"name":"many","age":22}
                  ]
      }
    ]

我可以像这样使用 filter() 来做到这一点吗：clients.reduce(//code hier)?

Answer 1

最简单的解决方案是遍历 clients 并检查具有相同 id 的现有对象。如果是，则推送到 clients 数组。否则，就创建一个。

var clients = [{ "id": 1, "name": "john", "age": 20 },
{ "id": 3, "name": "dean", "age": 23 },
{ "id": 12, "name": "harry", "age": 14 },
{ "id": 1, "name": "sam", "age": 22 },
{ "id": 13, "name": "olivia", "age": 16 },
{ "id": 7, "name": "sabi", "age": 60 },
{ "id": 7, "name": "sahra", "age": 40 },
{ "id": 4, "name": "natie", "age": 53 }, { "id": 7, "name": "kany", "age": 22 }]

const groups = [];

for (let client of clients) {
  const existingGroup = groups.find(group => group.id == client.id)
  if (existingGroup)
    existingGroup.clients.push(client);
  else {
    groups.push({ id: client.id, clients: [client] });
  }
}

console.log(groups);

您可以使用刚刚用于此目的的临时对象重新分配原始对象，并继续您的业务逻辑，我相信这就是您正在寻找的那个。

Answer 2

reduce() is tailor made for this. When you want to aggregate over an array and get a computed result, you should use reduce().

find()是另一种数组方法，它有助于根据条件查找数组元素（这里匹配id 属性）。

var clients=[{"id":1,"name":"john","age":20},
{"id":3,"name":"dean","age":23},
{"id":12,"name":"harry","age":14},
{"id":1,"name":"sam","age":22},
{"id":13,"name":"Bolivia","age":16},
{"id":7,"name":"sabi","age":60},
{"id":7,"name":"sahra","age":40},
{"id":4,"name":"natie","age":53},{"id":7,"name":"many","age":22}]


let ans = clients.reduce((agg,x,index) => {
 let findI = agg.find( a => 
  a.id === x.id
 );
 if(findI) findI.clients.push(x);
 else {
   agg.push({
     id : x.id,
     clients : [x] 
   });
 }
 return agg;
},[]);

console.log(ans);

如何获取数组中的重复对象？

How to get the duplicates objects in an array?

javascript

arrays

reduce