Mapping keys into objects with Javascript

Question

This is the object I have:

years = {1924:2, 1934: 10, 2010: 4}

I would like to transform this into:

years = [{year: 1924, items: 2}, {year: 1934, items: 10}, {year: 2010, items: 4}]

This is the code I came up with so far (which obviously doesn't work):

var years2 = {};

for (var i = 0; i < years.length; ++i) {
    years2.push({ years: [$key] })
};

I am stuggling to find the right way to access the unnamed keys and map these into their own objects.

(I am still learning JS and I know this is basics, but somehow cannot get my head around it.. )

anttud · Accepted Answer · 2022-06-10T10:06:46.477

1

You can create key value pairs from the object with Object entries and map them to new array

const years = {1924:2, 1934: 10, 2010: 4}


const ans = Object.entries(years).map(([key,value]) => {
  return {year: key, items: value}
})

console.log(ans);

edited Jun 10 '22 at 10:06

answered Jun 10 '22 at 10:04

anttud

736
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9

2

Code dumps are not *useful* answers. Say *what* you did, and *why*, before posting. – T.J. Crowder Jun 10 '22 at 10:05
Thanks! that works and slowly start to make sense to me too :) – Ant Jun 10 '22 at 10:28

score 1 · Answer 2 · answered Jun 10 '22 at 10:05

1

You can get entries, then convert to object with map

const years = {1924:2, 1934: 10, 2010: 4}
const result = Object.entries(years).map(([year, items]) => ({year: year, items: items}))
console.log(result)

answered Jun 10 '22 at 10:05

Xupitan

1,601
1
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Mapping keys into objects with Javascript

2 Answers2