javascript how to group and combine single array of object

Question

I have an array of object below,

 [ { locationCode: 'GMP', Qr: 46 }, { locationCode: 'CMT', Qr: 35 }, { locationCode: 'GMP', Cash: 29 }, { locationCode: 'CMT', Cash: 26 }, { locationCode: 'CMS', Qr: 22 }, { locationCode: 'CMT', Voucher: 6 }, { locationCode: 'CMS', Cash: 2 } ]

I want to group locationCode and combine others into one object like this

 [ { locationCode: 'GMP', Qr: 46, Cash: 29 }, { locationCode: 'CMT', Qr: 35, Cash: 26, Voucher: 6 }, { locationCode: 'CMS', Qr: 22, Cash: 2 } ]

Can someone explain that with Javascript or lodash, Thanks!

Answer 1

You can easily achieve this result using Map

 const arr = [ { locationCode: "GMP", Qr: 46 }, { locationCode: "CMT", Qr: 35 }, { locationCode: "GMP", Cash: 29 }, { locationCode: "CMT", Cash: 26 }, { locationCode: "CMS", Qr: 22 }, { locationCode: "CMT", Voucher: 6 }, { locationCode: "CMS", Cash: 2 }, ]; const map = new Map(); arr.forEach((o) => map.set(o.locationCode, {...(map.get(o.locationCode)?? {}), ...o }) ); const result = [...map.values()]; console.log(result);

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Answer 2

You can use Array.reduce to create an object keyed by locationCode , we'd also use object destructuring to assemble the object at each key value.

 const input = [ { locationCode: 'GMP', Qr: 46 }, { locationCode: 'CMT', Qr: 35 }, { locationCode: 'GMP', Cash: 29 }, { locationCode: 'CMT', Cash: 26 }, { locationCode: 'CMS', Qr: 22 }, { locationCode: 'CMT', Voucher: 6 }, { locationCode: 'CMS', Cash: 2 } ] const result = Object.values(input.reduce((acc, cur) => { acc[cur.locationCode] = acc[cur.locationCode] || { locationCode: cur.locationCode }; acc[cur.locationCode] = {...acc[cur.locationCode], ...cur }; return acc; }, {})) console.log('Result:', result);

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Answer 3

You could assign the object to an object, grouped by locationCode .

 const data = [{ locationCode: 'GMP', Qr: 46 }, { locationCode: 'CMT', Qr: 35 }, { locationCode: 'GMP', Cash: 29 }, { locationCode: 'CMT', Cash: 26 }, { locationCode: 'CMS', Qr: 22 }, { locationCode: 'CMT', Voucher: 6 }, { locationCode: 'CMS', Cash: 2 }], result = Object.values(data.reduce((r, o) => { Object.assign(r[o.locationCode]??= {}, o); return r; }, {})); console.log(result);

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