Combine array of objects into a single object with a nested object

Question

I'm trying to turn this data

[
  {
    key: 'myvar',
    value: 'my value',
    global: false,
  },
  {
    key: 'foo',
    value: 'bar',
    global: false,
  },
  {
    key: 'featureEnabled',
    value: true,
    global: true,
    accountId: 123,

  },
]

into this

{
  myvar: 'my value'
  foo: 'bar'
  123: { 'featureEnabled': true }
}

I was thinking something along the lines of something like below but this will return undefined for objects that don't have an accountId property. I thought there might be a way to use an if statement here.

const globalResponse = Object.assign({}, ...getPreference.map(o => ({ [o.accountId]: { [o.key]: o.value } })))

Use a for loop with an if condition. Object.assign with a map and a ternary will make it unreadable. — adiga
– adiga, Commented Jun 23, 2020 at 15:49

Orelsanpls · Accepted Answer · 2020-06-24 15:07:24Z

1

You can use of reduce to build your new object and setup specific triggers for specifics use cases.

function mutateObject(tmpBasis, key, value) {
  tmpBasis[key] = value;
  
  return tmpBasis;
}

const ret = [{
    key: 'myvar',
    value: 'my value',
    global: false,
  },
  {
    key: 'foo',
    value: 'bar',
    global: false,
  },
  {
    key: 'featureEnabled',
    value: true,
    global: true,
    accountId: 123,
  },
  {
    key: 'otherKey',
    value: true,
    global: true,
    accountId: 123,
  },
  {
    key: 'featureEnabled',
    value: true,
    global: true,
    accountId: 512,
  },
].reduce((tmp, {
  key,
  value,
  global,
  accountId,
}) => ({
  ...tmp,

  // If we are in global case, we either create an empty object containing the new key
  // or we add the new key inside of the existing object
  [global ? accountId : key]: global ? mutateObject(tmp[accountId] || {}, key, value) : value,
}), {});

console.log(ret);

edited Jun 24, 2020 at 15:07

answered Jun 23, 2020 at 15:50

Orelsanpls

23.7k7 gold badges46 silver badges74 bronze badges

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

6 Comments

Croisade Over a year ago

Thanks so much but I have a question. When I have two objects that have global set to true reduce is only returning the first object in the array. For example [ { key: 'featureEnabled',value: true,global: true,accountId: 123, }, { key: 'foo',value: 'bar' , global: true,accountId: 123, } ]

Orelsanpls Over a year ago

@Croisade It's because the accountId that is used as a key is the same! If you want to keep both value, either have different accountId or change the code to create an array behind the accoundId key.

Croisade Over a year ago

How would I change the code to create an array behind accountId? Sorry, a bit new.

Orelsanpls Over a year ago

@Croisade actually after rethinking your case, a simple object is a more suitable solution. See my edited code

Croisade Over a year ago

Thanks a lot for the help. I would really like to get better at stuff like this. Do you happen to know any resources I can use or maybe some keywords I can google so I can study this a bit more?

|

Girish Sasidharan · Accepted Answer · 2020-06-23 16:14:37Z

0

You can use reduce() with a condition inside like below

var myJSON = [{
    key: 'myvar',
    value: 'my value',
    global: false,
  },
  {
    key: 'foo',
    value: 'bar',
    global: false,
  },
  {
    key: 'featureEnabled',
    value: true,
    global: true,
    accountId: 123,

  },
];

let newJSON = myJSON.reduce((target, item) => {
  !!item.accountId ? target[item.accountId] = { [item.key]: item.value } : target[item.key] = item.value;
  return target;
}, {});

console.log(newJSON);

answered Jun 23, 2020 at 16:14

Girish Sasidharan

6021 gold badge6 silver badges15 bronze badges

Collectives™ on Stack Overflow

Combine array of objects into a single object with a nested object

2 Answers 2

6 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

6 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related