How to convert an array with one object and multiple keys into an array of multiple objects using those keys and their values?

Question

I have an array like so with a single object inside:

FirstArray = [{
    "category": "None",
    "ARFE": 553.5,
    "BV": 900,
    "RF rfeer": 0,
    .....
}]

I want to convert it so that every key-value pair (where the value is a number) in the object is in its own object like the following:

NewArray = [{
  name: "ARFE",
  value: 553.05
}, {
  name: "BV",
  value: 900
}, {
  name: "RF rfeer",
  value: 0
}, .....]

Here, each key was assigned a new key called name, and the value for the original key was assigned a new key called value. Those pairs are then put into their own object inside the array.

Note that "category": "None" is not its own object in the array since "None" is non-numerical.

It's also important to note that there could be many key-value pairs, so it's not just limited to the items above (e.g., "ARFE": 553.5, etc.)

What I have so far:

I know you can separate a single object into multiple objects:

NewArray = Object.entries(FirstArray).reduce((prev, [og, nw]) => {
    let [name, value] = og.match(/\D+|\d+$/g)
    prev[value] = { ...(prev[value] || {}), [name]: nw }
    return prev;
 }, {})

I also know how that you can create a new object with new keys like so:

NewArray = Object.assign(
    ...Object.entries(FirstArray).map(([key, value]) => ({ [key]: name }))
);

However, I'm having trouble putting everything together. How would I be able to achieve NewArray from FirstArray?

There is no JSON involved in this question. Please do not use the tag when discussing plain JavaScript objects. I've removed the tag from your question. — Heretic Monkey
– Heretic Monkey, Commented Aug 23, 2022 at 14:27
Does this answer your question? How to transpose a javascript object into a key/value array — Heretic Monkey
– Heretic Monkey, Commented Aug 23, 2022 at 14:28

Cerbrus · Accepted Answer · 2022-08-23 14:32:40Z

3

You were pretty close. All you needed to do is specify the name:

const data = {
    "category": "None",
    "ARFE": 553.5,
    "BV": 900,
    "RF rfeer": 0
};

const result = Object
    .entries(data)
    .filter(([_, value]) => typeof value === 'number')
    .map(([key, value]) => ({ name: key, value }));

console.log(result);

Also, if you don't want { "name": "category", "value": "None" } to be included in the result, you can just filter it:

const result = Object
    .entries(data)
    .filter(([ key ]) => key !== 'category')
    .map(([key, value]) => ({ name: key, value }));

edited Aug 23, 2022 at 14:32

answered Aug 23, 2022 at 14:24

Cerbrus

73.3k19 gold badges138 silver badges151 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

naru-magi Over a year ago

That works really well! Though I wrote that any key-value pair where the value is non-numerical (like "category": "None") have to be excluded from the final array. In such a case, would that require a foreach that encompasses all of the const result?

Cerbrus Over a year ago

@naru-magi: No, that can be filtered as well. I've updated my answer.

Konrad · Accepted Answer · 2022-08-23 14:25:40Z

0

Object.entries on array has no sense at all, use it on the object

const FirstArray = [{
  "category": "None",
  "ARFE": 553.5,
  "BV": 900,
  "RF rfeer": 0,
}]

const newObject = Object.entries(FirstArray[0]).reduce((array, [key, value]) => {
  return [...array, {
    name: key,
    value
  }]
}, [])

console.log(newObject)

answered Aug 23, 2022 at 14:25

Konrad

24.9k5 gold badges35 silver badges78 bronze badges

2 Comments

Cerbrus Over a year ago

Why are you using reduce to build the new array?

Konrad Over a year ago

Just by a mistake but it shows what op did wrong more clearly

albjerto · Accepted Answer · 2022-08-23 14:32:50Z

0

reduce is not the right way to go. Simply use map:

Object.entries(FirstArray[0])
    .filter(x => !isNaN(x[1]))    // filter out non-numeric values
    .map(([name, value]) => ({name, value}))

answered Aug 23, 2022 at 14:32

albjerto

5714 silver badges16 bronze badges

Collectives™ on Stack Overflow

How to convert an array with one object and multiple keys into an array of multiple objects using those keys and their values?

3 Answers 3

2 Comments

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related