Converting to Correct Object Format from Array

Question

I am aware of options like the spread operator and Object.assign() when it comes to converting an array to an object, however, I am having difficulty figuring out how to format the final object in the format I need.

My original array looks like this:

let propsArray = [ { id: '1' },
  { 'name.first': 'john' },
  { 'name.last': 'smith' } ]

The object I want from this data needs to look like this:

{
  "id" : 1,
  "name" : {
      "first" : "john",
      "last" : "smith"
  }
}

What I've tried so far, using object.assign(), ends up adding numbers as property keys in the resulting object, which is clearly not what I'm looking for:

  let finalObj = Object.assign({}, propsArray);

How can I get the resulting object formatted the way I need here?

If you control that initial array structure would be simpler to change it to have consistent key names in each object. As you can see from Nina's answer this is not trivial — charlietfl
– charlietfl, Commented Jul 10, 2019 at 20:10
Thanks, but in my case I can't because the array is going to be made up different elements each time. — Rey
– Rey, Commented Jul 10, 2019 at 20:12
Fine but if you do something like {propertyName: 'id', value:1}, {propertyName: 'first.name', value:'john'} it cuts complexity a lot. Or even use an object instead of array from the beginning — charlietfl
– charlietfl, Commented Jul 10, 2019 at 20:20

Nina Scholz · Accepted Answer · 2019-07-10 20:04:54Z

6

You need a deeper look into the object and take the splitted key and reduce them by taking an object with the property or an empty object. At the end assign the value.

var data = [{ id: '1' }, { 'name.first': 'john' }, { 'name.last': 'smith' }],
    result = data.reduce((r, o) => {
        Object.entries(o).forEach(([k, v]) => {
            var keys = k.split('.'),
                last = keys.pop();
            keys.reduce((q, k) => q[k] = q[k] || {}, r)[last] = v;        
        });
        return r;
    }, {});

console.log(result);

answered Jul 10, 2019 at 20:04

Nina Scholz

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Ghoul Ahmed · Accepted Answer · 2019-07-10 20:22:50Z

0

Try this:

const data = [
  {
    "id": "1"
  },
  {
    "name.first": "john"
  },
  {
    "name.last": "smith"
  }
]

const result = Object.entries(Object.assign({}, ...data))
.reduce((acc,[k,v])=>{
    [first, last] = k.split('.');
    if (!last) {
        acc[k] = v
    } else {
        acc[first] = acc[first] || {};
        acc[first][last] = v;
    }
    return acc
}, {})

console.log(result);

edited Jul 10, 2019 at 20:22

answered Jul 10, 2019 at 20:17

Ghoul Ahmed

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