JavaScript Object。 更改數組中對象的鍵名

Question

我有一個像這個例子一樣的對象數組：

[
  { id: 44, message: 'abcd', name: 'example1' },
  { id: 44, message: 'efgh', name: 'example2' },
  { id: 45, message: 'ijkl', name: 'example3' },
  { id: 45, message: 'mnop', name: 'example4' },
]

如您所見， id 值是重復的。 現在我只需要在第二次重復 object 時將“name”的鍵名更改為“lastName”：

[
  { id: 44, message: 'abcd', name: 'example1' },
  { id: 44, message: 'efgh', lastName: 'example2' },
  { id: 45, message: 'ijkl', name: 'example3' },
  { id: 45, message: 'mnop', lastName: 'example4' },
]

Answer 1

您可以保留last id跟蹤，並在map loop中modify返回 object

對於未排序的列表：

 let data = [ { id: 44, message: "abcd", name: "example1" }, { id: 44, message: "efgh", name: "example2" }, { id: 45, message: "ijkl", name: "example3" }, { id: 45, message: "mnop", name: "example4" }, ]; let idMap = new Set(); const result = data.map((item) => { if (idMap.has(item.id)) { const { name: lastName, ...rest } = item; item = {...rest, lastName }; } else { idMap.add(item.id); } return item; }); console.log(result);

注意：數據必須根據 id 進行排序。

 let data = [ { id: 44, message: "abcd", name: "example1" }, { id: 44, message: "efgh", name: "example2" }, { id: 45, message: "ijkl", name: "example3" }, { id: 45, message: "mnop", name: "example4" }, ]; let lastId = ""; const result = data.map((item) => { if (lastId === item.id) { const { name: lastName, ...rest } = item; item = {...rest, lastName }; lastId = ""; } else { lastId = item.id; } return item; }); console.log(result);

Answer 2

如果具有此 id 的項目已被訪問，您可以保存每個項目的id並將鍵從name重命名為lastName 。

 let list = [ { id: 44, message: 'abcd', name: 'example1' }, { id: 44, message: 'efgh', name: 'example2' }, { id: 45, message: 'ijkl', name: 'example3' }, { id: 45, message: 'mnop', name: 'example4' }, ]; let checked = []; list.forEach(function (item) { if(checked.includes(item.id)){ item['lastName'] = item['name']; delete item['name']; }else{ checked.push(item.id); } }); console.log(list)