json数据检查是否重复相同的id

Question

我有一个json数据，其中一个id有不同的color_id。所以从那里我只想检查同一个id是否重复然后只保留第一个

这是我的示例JSON

var data= [{ "id": "1", "name": "xxx", "age": "22","color_id": "22" },
    { "id": "1", "name": "yyy", "age": "15","color_id": "1" },
    { "id": "5", "name": "zzz", "age": "59","color_id": "22" }];

我想要的输出

var data= [{ "id": "1", "name": "xxx", "age": "22","color_id": "22" },
    { "id": "5", "name": "zzz", "age": "59","color_id": "22" }];

我尝试减少但在那里我发现修改数据结构所以我不确定我是否会得到我想要的输出。

Answer 1

var data = [{
    "id": "1",
    "name": "xxx",
    "age": "22",
    "color_id": "22"
  },
  {
    "id": "1",
    "name": "yyy",
    "age": "15",
    "color_id": "1"
  },
  {
    "id": "5",
    "name": "zzz",
    "age": "59",
    "color_id": "22"
  }
];

let map = {};
let uniqueEntries = data.filter((el) => map[el.id] ? false : map[el.id] = true);
console.log(uniqueEntries )

阐释：

1. 您创建我们存储ID的地图。
2. 然后过滤数组，每当我们找到一个不在地图中的条目时，我们将它添加到列表中并返回true。如果我们已经在列表中有它，我们返回false以丢弃该条目。

条件的最后一部分是使用赋值返回赋值的事实。

Answer 2

您可以使用reduce创建一个新数组，并在这个新数组中使用findIndex来检查这个新数组是否有一个具有相同id的对象。如果存在具有相同id的对象，则不要推送具有相同id的另一个对象

var data = [{
    "id": "1",
    "name": "xxx",
    "age": "22",
    "color_id": "22"
  },
  {
    "id": "1",
    "name": "yyy",
    "age": "15",
    "color_id": "1"
  },
  {
    "id": "5",
    "name": "zzz",
    "age": "59",
    "color_id": "22"
  }
];
let m = data.reduce(function(acc, curr) {
  let findIndex = acc.findIndex(function(item) {
    return item.id === curr.id
  })
  if (findIndex === -1) {
    acc.push(curr)

  }
  return acc;
}, [])

console.log(m)

Answer 3

使用Array.reduce和Array.some

const data = [{
    id: '1',
    name: 'xxx',
    age: '22',
    color_id: '22',
  },
  {
    id: '1',
    name: 'yyy',
    age: '15',
    color_id: '1',
  },
  {
    id: '5',
    name: 'zzz',
    age: '59',
    color_id: '22',
  },
];

const reduced = data.reduce((tmp, x) => {
  if (tmp.some(y => y.id === x.id)) return tmp;

  return [
    ...tmp,

    x,
  ];
}, []);

console.log(reduced);

---

或者Array.filter，因为@JGoodgive是一个好主意，但有点不同

    const data = [{
        id: '1',
        name: 'xxx',
        age: '22',
        color_id: '22',
      },
      {
        id: '1',
        name: 'yyy',
        age: '15',
        color_id: '1',
      },
      {
        id: '5',
        name: 'zzz',
        age: '59',
        color_id: '22',
      },
    ];

    const reduced = data.filter((x, xi) => !data.slice(0, xi).some(y => y.id === x.id));

    console.log(reduced);

Answer 4

您可以使用Set来跟踪已处理的ID。

const
  // The data set with non-unique IDs
  data= [{ "id": "1", "name": "xxx", "age": "22","color_id": "22" }, { "id": "1", "name": "yyy", "age": "15","color_id": "1" }, { "id": "5", "name": "zzz", "age": "59","color_id": "22" }];
  
function dedupe(items) {
  // Create a set to keep track of IDs already encountered.
  const
    idSet = new Set();
  // Filter the items, when an ID isn't in the set add it to the set and return true
  // so item is in the result array. When the ID is in the set return false so the 
  // item will be dropped.
  return items.filter(item => {
    // If the ID is already in the set, drop it from the result. This way only the
    // first item with an ID is added to the result.
    if (idSet.has(item.id)) {
      return false;
    }
    
    // Add the ID to the set, this way we keep track of the IDs already encountered.
    idSet.add(item.id);
    // Return true so the item is included in the result array.
    return true;
  });
}    

console.log(dedupe(data));