How to rename key of object with a variable?

Question

I have got an object:

blocks: [
  {
    type: 'animal',
    data: { text: 'Bark bark' }
  },
  {
    type: 'human',
    data: { text: 'Speak speak' }
  },
  ...
]

The data: naming does not fit my needs and I would like to rename it with the type value. So It should look like this:

blocks: [
  {
    type: 'animal',
    animal: { text: 'Bark bark' }
  },
  {
    type: 'human',
    human: { text: 'Speak speak' }
  },
  ...
]

How can I achieve this with very little code of javascript? My solution does work but seems to be stupid (especially if you consider 10+ different kind of types):

const blocks = [];
oldBlocks.map(block => {
    const {type, data} = block;
    blocks.push({
        type: type,
        animal: type === "animal" ? data : undefined,
        human: type === "human" ? data : undefined,
        ....
    });
});

@sideshowbarker you are right, this is somehow a duplicate and I found the linked thread, but I was not able to understand it. Luckily zfrisch nailed it down to the most simple example :-) — Marian Rick, Aug 15 '19 at 22:41

score 2 · Accepted Answer · answered Aug 15 '19 at 17:34

2

Use brackets to denote an expression inside of an object, allowing you to evaluate variables as key names:

blocks.map(({type, data}) => ({ type, [type]: data }));

Example:

let blocks = [
  {
    type: 'animal',
    data: { text: 'Bark bark' }
  },
  {
    type: 'human',
    data: { text: 'Speak speak' }
  }
],


result = blocks.map(({type, data}) => ({ type, [type]: data }));

console.log(result);

answered Aug 15 '19 at 17:34

zfrisch

8,474
1
22
34

Thanks a lot @zfrisch, that's as simple as it could be. Thanks for letting me know :-) – Marian Rick Aug 15 '19 at 22:40

score 1 · Answer 2 · answered Aug 15 '19 at 17:40

1

A possible Solution:

for i in blocks:
i["'"+i[type]+"'"]=i['data']
delete(i['data'])

answered Aug 15 '19 at 17:40

Divanshu Aggarwal

416
6
13

How to rename key of object with a variable?

2 Answers2

Example: