Transform array into object with array values

Question

I need to transform this array

[ { _id: 'indoor', count: 12 }, { _id: 'outdoor', count: 34 } ]

into this result:

{ label: ['in', 'out'], data: [12, 34]}

So I need to get the labels (_id) in an array and replace them with some individual text and I need to get the values as data array. The order of both should be the same of course.

For the second part I would do something like

array.map(c => c.count)

I can do the same thing with the label value, but how do I use individual text? E.g. 'indoor' should be replaced by 'car' and 'outdoor' should replaced by 'plane'.

StepUp · Accepted Answer · 2019-10-29 07:24:19Z

1

You can use reduce method:

let sourceData = [
    { _id: 'indoor', count: 12 },
    { _id: 'outdoor', count: 34 }
];

const maps = {indoor: 'in', outdoor: 'out'};    

const result = sourceData.reduce((a, c) => {
    a.label = a.label || [];
    a.data = a.data || [];

    a.label.push(maps[c._id]);
    a.data.push(c.count);

    return a;
}, {});

console.log(result);

You can sort your desired array in custom order:

let sourceData = [
    { _id: 'indoor', count: 12 },
    { _id: 'outdoor', count: 34 }
];

const maps = {indoor: 'in', outdoor: 'out'};    

const result = sourceData.reduce((a, c) => {
    a.label = a.label || [];
    a.data = a.data || [];

    a.label.push(maps[c._id]);
    a.data.push(c.count);

    return a;
}, {});

result.label.sort((a, b) => {
  const order = {'out': 1, 'in': 2, undefined: 3};
  return order[a] - order[b];
});

console.log(`custom order of labels: `, result);

edited Oct 29, 2019 at 7:24

answered Oct 28, 2019 at 19:16

StepUp

38.5k16 gold badges95 silver badges159 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

user3142695 Over a year ago

Would it be possible to change the order of the data by a given label order? For example if I want to get the 'out' value at first position and of course there are more data values...

StepUp Over a year ago

@user3142695 yeah, it is possible

user3142695 Over a year ago

But not with the reduce function as it is used in your answer, isn't it?

junvar · Accepted Answer · 2019-10-28 19:05:40Z

1

let labels = {
  indoor: 'car',
  outdoor: 'plaine'
};

let input = [{
  _id: 'indoor',
  count: 12
}, {
  _id: 'outdoor',
  count: 34
}];
let output = input.reduce((output, inObj) => {
  output.label.push(labels[inObj._id]);
  output.data.push(inObj.count);
  return output;
}, {
  label: [],
  data: []
});

console.log(output);

answered Oct 28, 2019 at 19:05

junvar

11.6k2 gold badges35 silver badges52 bronze badges

Comments

OlegI · Accepted Answer · 2019-10-28 19:16:53Z

1

const data = 
[ 
  { _id: 'indoor', count: 12 }, 
  { _id: 'outdoor', count: 34 } 
]
const result = {
  label: data.map(a => a._id.replace('door','')),
  data: data.map(e => e.count)
}

console.log(result)

answered Oct 28, 2019 at 19:16

OlegI

6,1204 gold badges27 silver badges36 bronze badges

Comments

brk · Accepted Answer · 2019-10-28 19:06:43Z

0

In the map call back you can check the text and return the required string

let data = [{
  _id: 'indoor',
  count: 12
}, {
  _id: 'outdoor',
  count: 34
}]

let newData = {
  label: data.map((item) => {
    if (item._id === 'indoor') {
      return 'in';
    } else {
      return 'out';
    }

  }),
  data: data.map(item => item.count)

};
console.log(newData)

answered Oct 28, 2019 at 19:06

brk

50.3k10 gold badges59 silver badges85 bronze badges

Comments

Nenad Borovčanin · Accepted Answer · 2019-10-28 19:12:50Z

0

const data = [ { _id: 'indoor', count: 12 }, { _id: 'outdoor', count: 34 } ];

const indoor = data.filter((item) => item._id === 'indoor').map((i) => i.count);
const outdoor = data.filter((item) => item._id === 'outdoor').map((i) => i.count);

const res = { label: ['in', 'out'], data: [...indoor, ...outdoor]};

console.log(res);

Will give you next:

{
  label: [
    "in",
    "out"
  ],
  data: [
    12,
    34
  ]
}

answered Oct 28, 2019 at 19:12

Nenad Borovčanin

92 bronze badges

Comments

Federico · Accepted Answer · 2019-10-28 19:20:22Z

0

const arr = [ { _id: 'indoor', count: 12 }, { _id: 'outdoor', count: 34 } ];   
arr.map(o => [o._id === 'indoor' ? 'in' : 'out', o.count])
    .reduce((p, c) => ({
        label: [...p.label, c[0]]),
        data: [...p.data, c[1]])
    }), {
        label: [],
        data: []
    })

edited Oct 28, 2019 at 19:20

answered Oct 28, 2019 at 19:12

Federico

3,9905 gold badges38 silver badges50 bronze badges

Collectives™ on Stack Overflow

Transform array into object with array values

6 Answers 6

3 Comments

Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

6 Answers 6

3 Comments

Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related