TS,JS 如何快速判断出数据list中某个字段值 ,是否有重复?(基础问题)

Question

如题.有如下list,如何判断,其中的Name字段值 ,是否有重复?
(下面数据有重复,即有两条Name字段的值为 name2)

打扰各位了.
data:

[
  {
    "Name": "name1",
    "id": "3325121b",
    "index": 0
  },
  {
    "Name": "name2",
    "id": "0ad74ac0",
    "index": 1
  },
  {
    "Name": "name2",
    "id": "0f6ad980",
    "index": 2
  }
]

Answer 1

不知道你想得到什么结果，下面得到的是所有重复的Name值

const data = [
  {
    "Name": "name1",
    "id": "3325121b",
    "index": 0
  },
  {
    "Name": "name2",
    "id": "0ad74ac0",
    "index": 1
  },
  {
    "Name": "name2",
    "id": "0f6ad980",
    "index": 2
  }
];

const nameIndex = data.reduce((acc, item) => {acc[item.Name] = (acc[item.Name] || 0) + 1; return acc;}, {});

Object.keys(nameIndex).filter(i => nameIndex[i] > 1);

Answer 2

思路供参考

const containDuplicate = (arr, prop) =>
  arr.reduce((m, x) => m.set(x[prop], x), new Map()).size !== arr.length

const data = [
  {
    "Name": "name1",
    "id": "3325121b",
    "index": 0
  },
  {
    "Name": "name2",
    "id": "0ad74ac0",
    "index": 1
  },
  {
    "Name": "name2",
    "id": "0f6ad980",
    "index": 2
  }
]

console.log(containDuplicate(data, 'Name'))