convert array of arrays to key value pairs using plain JavaScript or jQuery

Question

I have Array of Array in JavaScript as follows:

myarr = [Array(3), Array(3)]

It has values:

[
 ['ID', 'Name', 'BloodGroup'],
 [1, 'Jim', 'B+'],
 [2, 'Jane', 'A+']
]

I want array of object as:

[{'ID':1,'Name':'Jim', 'BloodGroup': 'B+'}, ....]

Is there any way to achieve this using plain js or jQuery without using for loop, as data I get might be big, and server side is not an option.

Please visit the [help], take the [tour] to see what and [ask]. Do some research, search for related topics on SO; if you get stuck, post a [mcve] of your attempt, noting input and expected output using the `[<>]` snippet editor. — mplungjan, Jun 04 '20 at 14:12
@Sfili_81 I had crude logic with for loops, but performance wise need different solution, I searched various similar questions here with map reduce, but those weren't too helpful in my case — elpidaguy, Jun 04 '20 at 14:13
Why not do this on the server that creates the arrays? It looks like CSV — mplungjan, Jun 04 '20 at 14:14
@mplungjan i am reading excel in javascript using readXlsxFile, its the output of the same, i need to validate it on client side hence wanted json array — elpidaguy, Jun 04 '20 at 14:17
What makes you think that using a for loop is bad when the data is big? — Heretic Monkey, Jun 04 '20 at 14:18

mplungjan · Accepted Answer · 2020-06-04T15:04:53.300

Destructing is perhaps a way to go?

const arr = [
  ['ID', 'Name', 'BloodGroup'],
  [1, 'Jim', 'B+'],
  [2, 'Jane', 'A+']
]
const titles = data[0]; // not used yet
const obj = arr.slice(1).map(([ID, Name, BloodGroup]) => ({ ID, Name, BloodGroup }))
console.log(obj)

I think I might miss one more level of abstraction using the titles but I am still investigating

@NinaScholz got me a more abstract example

const arr = [
  ['ID', 'Name', 'BloodGroup'],
  [1, 'Jim', 'B+'],
  [2, 'Jane', 'A+']
]
const titles = arr[0]; 

const obj = arr.slice(1).map(
  arr => Object.fromEntries(
    titles.map( 
      (t, i) => [t, arr[i]] 
    )
  )
);

console.log(obj)

convert array of arrays to key value pairs using plain JavaScript or jQuery

1 Answers1