CODEWITHSUNDEEP
javascriptarraystypescriptobjectlodash
Vortex
Vortex

Reputation: 33

How to correctly use the lodash to group an object inside an array?

I have an array of objects like this:

[ { key: 'particles', value: 'GN' },
  { key: 'particles', value: 'TR' },
  { key: 'wave', value: 'AB' },
  { key: 'sense', value: 'TU' } ]

I need to get to something like:

[ { system.particles: ['GN', 'TR'] }, system.wave: {'AB'}, system.sense: {'TE'} } ]

I have tried to use lodash as I have seen from examples using the groupBy function. But I haven't been able to get what I want, which includes the key name changes.

This is a part of my code:

let exo = _.mapValues(_.groupBy(desc, 'key'),
    clist => clist.map(tags => _.omit(desc, ['key'])))

But I only get this, which is not what I'm looking for

{ particles: [ { value: 'GN' }, { value: 'TR' } ],
  wave: [ { value: 'AB' } ],
  sense: [ { value: 'TU' } ] }

Upvotes: 1

Views: 138

Answers (1)

Vinay
Vinay

Reputation: 2339

You can map like this

const data = [
  { key: 'particles', value: 'GN' },
  { key: 'particles', value: 'TR' },
  { key: 'wave', value: 'AB' },
  { key: 'wave', value: 'ABC' },
  { key: 'wave', value: 'ABD' },
  { key: 'sense', value: 'TU' }
];

const groupedData = _.map(_.groupBy(data, 'key'), (value, key) => {
   const newKey = 'system.' + key;

   return {[newKey]: _.map(value, 'value') };
});

console.log(groupedData);
<script src="https://cdn.jsdelivr.net/npm/[email protected]/lodash.min.js"></script>

Upvotes: 1

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