How to get list of all objects in an array of objects?

Question

I have an array of object such that every element has unique objects. How can I make a list of all those unique elements? Eg

const obj = [
  {
    a: 'a',
    b: 'b',
  },
  {
    c: 'c',
    d: 'd',
  },
  {
    e: 'e',
    f: 'f',
  },
];

I want an array of keys - [a,b,c,d,e,f]

[Get array of object's keys](https://stackoverflow.com/q/8763125) + [Merge/flatten an array of arrays](https://stackoverflow.com/q/10865025) + [Get all unique values in a JavaScript array (remove duplicates)](https://stackoverflow.com/q/1960473) — VLAZ, Mar 04 '21 at 11:56
i am really surprised why this question gets upvotes. it is unclear what op is looking for, because of the same strings for key and value and op has not included some code which does not work. — Nina Scholz, Mar 04 '21 at 12:03

score 1 · Answer 1 · answered Mar 04 '21 at 11:54

First of all you need to rotate your loop of array then you need to rotate your json loop.

const obj = [{
 a:'a',
 b:'b',   
},
{
 c:'c',
 d:'d',   
},
{
 e:'e',
 f:'f',   
}]
let keys = [];
for(let i= 0; i < obj.length; i++){
  for(let key in obj[i]){
    keys.push(key);
  }
}
console.log(keys);

score 1 · Answer 2 · answered Mar 04 '21 at 11:54

1

const obj = [{
 a:'a',
 b:'b',   
},
{
 c:'c',
 d:'d',   
},
{
 e:'e',
 f:'f',   
}]

const res = obj.map(a=> Object.values(a)).flat()

console.log(res)

answered Mar 04 '21 at 11:54

ptothep

415
3
10

score -2 · Answer 3 · answered Mar 04 '21 at 11:55

-2

let array = []
obj.map((values, index) => {
    array = [...Object.keys(values), ...array]
})

try the above code and comment if any doubt

answered Mar 04 '21 at 11:55

Vijay

228
3
8

How to get list of all objects in an array of objects?

3 Answers3