JavaScript Object.values from an array of object

Question

Here is my object:

const arr = [
  { name: 'Breaking Bad S01E07' },
  { name: 'Breaking Bad S01E06' },
  { name: 'Dexter S01E05' },
  { name: 'Dexter S01E02' },
  { name: 'Dexter S01E07' },
];

I want to extract just values and I used Object.values but it don't change.

Here is my code:

val = Object.values(arr);
console.log(val);

But what I get is exactly the same without Object.values. It doesn't return values. I returns keys + values.

I used map on it cuz it is an array of objects but it returns undefined!

const map = arr.map((x) => {
  Object.values(x);
});
console.log(map);

here is what I get:

[ undefined, undefined, undefined, undefined, undefined ]

Your function in the `map()` isn't returning anything. Try `return Object.values(x);` — Barmar, Dec 17 '21 at 17:57

score 0 · Accepted Answer · answered Dec 17 '21 at 17:56

You will need to map and then destructure the name from each object.

const arr = [
  { name: 'Breaking Bad S01E07' },
  { name: 'Breaking Bad S01E06' },
  { name: 'Dexter S01E05' },
  { name: 'Dexter S01E02' },
  { name: 'Dexter S01E07' },
];

const values = arr.map(({ name }) => name);

console.log(values);

If you want all the values without their keys, you could try reducing the values.

const arr = [
  { name: 'Breaking Bad S01E07' },
  { name: 'Breaking Bad S01E06' },
  { name: 'Dexter S01E05' },
  { name: 'Dexter S01E02' },
  { name: 'Dexter S01E07' },
];

const values = arr.reduce((acc, obj) => [...acc, ...Object.values(obj)], []);

console.log(values);

Motoralfa · Answer 2 · 2021-12-17T18:06:55.577

0

The map function should always return a value.
You can change your map function in this way.

const map = arr.map((x) => Object.values(x));
console.log(map);

edited Dec 17 '21 at 18:06

answered Dec 17 '21 at 17:58

Motoralfa

450
3
10

score 0 · Answer 3 · answered Dec 17 '21 at 17:58

You are not returning anything from map callback function, hence, it populates the resultant array with undefined

const arr = [
  { name: 'Breaking Bad S01E07' },
  { name: 'Breaking Bad S01E06' },
  { name: 'Dexter S01E05' },
  { name: 'Dexter S01E02' },
  { name: 'Dexter S01E07' },
];

// Using object.values

const val = arr.map(item => Object.values(item)[0]);

// OR Accessing value directly
const values = arr.map(item => item.name)


console.log(values, val);

score 0 · Answer 4 · answered Dec 17 '21 at 17:58

The callback function in map() needs to return something.

const map = arr.map((x) => {
  return Object.values(x);
});

Or you can use the shorthand format that automatically returns an expression by leaving out the {} around the body:

const map = arr.map((x) => Object.values(x));

JavaScript Object.values from an array of object

4 Answers4