How to reconstruct array of objects based on duplicate keys?-CodePudding

I'm getting an array object that looks like this. My goal is to combine or merge them based on duplicate keys.

documents: [
    {
        image: 'sample image 1',
        id_side: 'Front',
        type: 'Passport'
    },
    {
        image: 'sample image 2',
        id_side: 'Back',
        type: 'Passport'
    },
    {
        image: 'sample image 3',
        id_side: 'Back',
        type: 'License'
    }
]

How can I arrange it to look like this?

documents: [
    {
        documentType: 'Passport',
        requiredDocs: [
            {
                image: 'sample image 1',
                id_side: 'Front',
                type: 'Passport'
            },
            {
                image: 'sample image 2',
                id_side: 'Back',
                type: 'Passport'
            }
        ]
    },
    {
        documentType: 'License',
        requiredDocs: [
            {
                image: 'sample image 3',
                id_side: 'Back',
                type: 'License'
            }
        ]
    }
]

I have found a similar question but I can't seem to make it work in my case. See the similar question in this link: How to merge/combine array of objects based on duplicate keys?

CodePudding user response：

Use reduce() to create an accumulation object, and then map() the entries of that object to your desired output format:

const data = [{
  image: 'sample image 1',
  id_side: 'Front',
  type: 'Passport'
}, {
  image: 'sample image 2',
  id_side: 'Back',
  type: 'Passport'
}, {
  image: 'sample image 3',
  id_side: 'Back',
  type: 'License'
}];

const result = Object.entries(data.reduce((a, v) => ({
  ...a,
  [v.type]: [...a[v.type] || [], v]
}), {})).map(([documentType, requiredDocs]) => ({
  documentType,
  requiredDocs
}));

console.log(result);

CodePudding user response：

const obj={documents:[{image:'sample image 1',id_side:'Front',type:'Passport'},{image:'sample image 2',id_side:'Back',type:'Passport'},{image:'sample image 3',id_side:'Back',type:'License'}]};

let types = obj.documents.reduce((a, { type, ...r }) => {
  a[type] = a[type] || [];
  a[type].push({ type, ...r });
  return a;
}, {});

let result = Object.entries(types).map(([ documentType, requiredDocs ]) => ({ documentType, requiredDocs }));

console.log(result);

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