Get a one-dimensional array from an array of objects

I have the following array of objects:

const input = [
  { key1: 1, key2: 1, key3: 5 },
  { key1: 2, key2: 5, key3: 6 },
  { key1: 4, key2: 6, key3: 7 },
  { key1: 7, key2: 8, key3: 9 },
];

I just want to loop through an array of objects and collect all the values ​​into a one dimensional array like this:

const output = [1, 1, 5, 2, 5, 6, 4, 6, 7, 7, 8, 9];

Can someone help solve this problem?

>Solution :

If the keys are always in that order, you can use Object.values as a callback to flatMap

const output = input.flatMap(Object.values)

const input = [
  { key1: 1, key2: 1, key3: 5 },
  { key1: 2, key2: 5, key3: 6 },
  { key1: 4, key2: 6, key3: 7 },
  { key1: 7, key2: 8, key3: 9 },
];

const output = input.flatMap(Object.values)

console.log(output)

Relying the order of keys in an object is generally NOT a good idea. You can destrcuture all the properties you need and flatten them in that order:

input.flatMap(({ key1, key2,  key3 }) => [key1, key2, key3])

or

Create an array of keys to make it a bit more dynamic:

const keys = ["key1", "key2", "key3"]
const output = input.flatMap(o => keys.map(k => o[k]))