根据属性值删除对象数组中的重复项

Question

我有一组对象，我试图根据某些属性（第一个和最后一个）查找重复项。我的逻辑似乎是错误的，这是我尝试过的。

我的最终结果应该类似于：

[
  {first:"John", last: "Smith", id:"1234", dupes: [555,666]},
  {first:"John", last: "Jones", id:"333", dupes: []}
];

let arrayOfObjects = 
[
  {first:"John", last: "Smith", id:"1234", dupes: []},
  {first:"John", last: "Smith", id:"555", dupes: []},
  {first:"John", last: "Jones", id:"333", dupes: []},
  {first:"John", last: "Smith", id:"666", dupes: []}
];


arrayOfObjects.forEach(record => {
  arrayOfObjects.forEach(rec => {
  if(record.first == rec.first &&
      record.last == rec.last &&
      record.id !== rec.id){
        console.log("match found for: " + JSON.stringify(record) + " and: " + JSON.stringify(rec));
        
        record.dupes.push(rec.id);
        //probably need to remove something here
      }
  });
});

console.log(JSON.stringify(arrayOfObjects));

Answer 1

首先，请don't use .map() when not performing a mapping operation。我已将.map 的用法替换为.forEach，因为后者更适合这种情况。

其次，您的评论 //probably need to remove something here 是正确的 - 您必须删除一个项目。即，您必须删除刚刚找到的重复项rec。为此，您可以使用需要删除索引的Array#splice。可以轻松获取索引as the second parameter of the .forEach() callback

let arrayOfObjects = 
[
  {first:"John", last: "Smith", id:"1234", dupes: []},
  {first:"John", last: "Smith", id:"555", dupes: []},
  {first:"John", last: "Jones", id:"333", dupes: []},
  {first:"John", last: "Smith", id:"666", dupes: []}
];


arrayOfObjects.forEach(record => {
  arrayOfObjects.forEach((rec, index) => {
// get index ------------------^^^^^-->------------------>--------------v
  if(record.first == rec.first &&       //                              |
      record.last == rec.last &&        //                              |
      record.id !== rec.id){            //                              |
        record.dupes.push(rec.id);      //                              |
        arrayOfObjects.splice(index, 1) //<--- remove using the index --<
      }
  });
});

console.log(JSON.stringify(arrayOfObjects));