从对象数组中收集键并将其减少为单个数组并删除重复项答案

【问题标题】：Collecting the keys from array of objects and reducing it into a single array and removing duplicates从对象数组中收集键并将其减少为单个数组并删除重复项
【发布时间】：2019-05-23 12:21:24
【问题描述】：

我正在尝试提取数组中每个对象的键，然后我将收集所有键，然后连接小块键数组。然后我使用 set 消除重复并获取所有键。

我能够得到结果。有没有更好的方法来解决这个问题

任何帮助表示赞赏

let data = [
  {
    "test1": "123",
    "test2": "12345",
    "test3": "123456"
  },
  {
    "test1": "123",
    "test2": "12345",
    "test3": "123456"
  },
  {
    "test1": "123",
    "test2": "12345",
    "test3": "123456"
  },
  {
    "test1": "123",
    "test2": "12345",
    "test3": "123456"
  },
  {
    "test1": "123",
    "test2": "12345",
    "test3": "123456"
  },
]

let keysCollection = []

data.forEach(d => {
  let keys = Object.keys(d);
  keysCollection.push(keys)
})


let mergingKeysCollection = keysCollection.reduce((a,b) => [...a, ...b], [])

let uniqueKeys = new Set(mergingKeysCollection)

console.log('uniqueKeys', uniqueKeys)

【问题讨论】：

你所做的实际上是有效的，只是集合没有字符串化..所以让你的工作只是做 -> let uniqueKeys = Array.from(new Set(mergingKeysCollection)) 甚至 let uniqueKeys = [...new Set(mergingKeysCollection))]
@Keith 或console.log('uniqueKeys', Array.from(uniqueKeys))

标签： javascript arrays

【解决方案1】：

您可以直接获取一个集合，而无需使用另一个键数组。

let data = [{ test1: "123", test2: "12345", test3: "123456" }, { test1: "123", test2: "12345", test3: "123456" }, { test1: "123", test2: "12345", test3: "123456" }, { test1: "123", test2: "12345", test3: "123456" }, { test1: "123", test2: "12345", test3: "123456" }],
    uniqueKeys = Array.from(
        data.reduce((r, o) => Object.keys(o).reduce((s, k) => s.add(k), r), new Set)
    );

console.log(uniqueKeys)

【讨论】：

【解决方案2】：

const data = [{"test1":"123","test2":"12345","test3":"123456"},{"test1":"123","test2":"12345","test3":"123456"},{"test1":"123","test2":"12345","test3":"123456"},{"test1":"123","test2":"12345","test3":"123456"},{"test1":"123","test2":"12345","test3":"123456"},];

const res = data.reduce((unique, item) => (Object.keys(item).forEach(key => unique.add(key)), unique), new Set);

console.log([...res]);

.as-console-wrapper {min-height: 100%}

【讨论】：