将对象数组内的每个对象的键获取到数组中：Javascript

Question

I have an object with the following format

var obj = [{
  "a": 1
}, {
  "b": 2
}, {
  "c": 3
}];

Would want to fetch only keys out of each object inside this array of objects into a new array

Something like this: ["a","b","c"]

Have tried the following but it is not working :

 var obj = [{ "a": 1 }, { "b": 2 }, { "c": 3 }]; let result = obj.map (({ val }) => val) console.log(result); 

Answer 1

Merge to a single object by spreading into Object.assign() , and then get the keys:

 var obj = [{"a":1},{"b":2},{"c":3}]; const result = Object.keys(Object.assign({}, ...obj)); console.log(result); 

Or use Array.flatMap() with Object.keys() :

 var obj = [{"a":1},{"b":2},{"c":3}]; const result = obj.flatMap(Object.keys); console.log(result); 

Answer 2

I'd .map and extract the first item in the Object.keys of the object being iterated over:

 var obj = [{ "a": 1 }, { "b": 2 }, { "c": 3 }]; const result = obj.map(inner => Object.keys(inner)[0]); console.log(result); 

Answer 3

You can make use of Object.assign and spread(...) operator to solve this issue

 var mainObj = [{"a":1},{"b":2},{"c":3},{"23":1},{"32b":2},{"232c":3}]; const allKeys = Object.keys(Object.assign({}, ...mainObj)); console.log(allKeys); 

Answer 4

You can simply use .map() to open the array and then use Object.keys to return the key from the object. Please refer the example I have made.I hope it helps

https://www.w3schools.com/code/tryit.asp?filename=G66AEBM9ZJCD

let object1 = [{a:1,b:2,c:3}]
        let final = object1.map(function(object){ 
            return Object.keys(object)
        });