JavaScript從對象

Question

我有這個數組的數組獲取密鑰的陣列，陣列中的每個對象只有一個關鍵：

[{ "hello": "value1" }, { "there": "value2" }, { "everybody": "value3" }] 

我想所有鍵提取到一個數組，使得結果我要的是：

["hello", "there", "everybody"] 

是什麼在Lodash或香草的JavaScript（最好ES6）這樣做的簡潔的方式？

Answer 1

結合使用Object#assign單個對象，並使用Object#keys檢索對象的鍵：

const arr = [{ "hello": "value1" }, { "there": "value2" }, { "everybody": "value3" }]; 
 

 
const keys = Object.keys(Object.assign({}, ...arr)); 
 

 
console.log(keys);

而且使用lodash年代ES5版本_.assign()與_.spread()合併到單個對象，並_.keys()領取鑰匙：

var arr = [{ "hello": "value1" }, { "there": "value2" }, { "everybody": "value3" }]; 
 

 
var keys = _.keys(_.spread(_.assign)(arr)) 
 

 
console.log(keys); 
 
    
 

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Answer 2

您可以使用Array#map以及Object.keys。

let arr = [{ "hello": "value1" }, { "there": "value2" }, { "everybody": "value3" }]; 
 

 
let keys = [].concat(...arr.map(Object.keys)); 
 

 
console.log(keys);

Answer 3

您可以使用數組map與對象keys結合：

const array = [{ "hello": "value1" }, { "there": "value2" }, { "everybody": "value3" }]; 

const result = array.map((el) => Object.keys(el)[0]); 

Answer 4

var x = [{ "hello": "value1" }, { "there": "value2" }, { "everybody": "value3" }]; 
 

 
console.log(x.map(function(obj){return Object.keys(obj)[0]}));

Answer 5

這裏有一個解決方案使用lodash的flatMap：

let result = _.flatMap(data, _.keys); 

Answer 6

這個土生土長的ES5解決方案，它保留了重複鍵是：

var objects = [{ "hello": "value1" }, { "there": "value2" }, { "everybody": "value3" }]; 
var keys = []; 
for (var obj in objets) { 
    keys.push(Object.keys(obj)[0]); 
}