JavaScript - How to change object keys in an array of object?

Question

I have an array of object :

let data = [
  { "date" : "17/03/2022", "count" : 2, "[email protected]" : 2 },
  {
    "date" : "17/05/2022",
    "count" : 2,
    "[email protected]" : 1,
    "[email protected]" : 1
  },
  { "date" : "17/07/2022", "count" : 7, "[email protected]" : 7 },
];

I would like to remove "@" in the object key instead of the email address.

This is the expected output :

// Expected output:
data = [
  { "date" : "17/03/2022", "count" : 2, "james" : 2 },
  {
    "date" : "17/05/2022",
    "count" : 2,
    "admin" : 1,
    "secretary" : 1
  },
  { "date" : "17/07/2022", "count" : 7, "staff" : 7 },
];

Notes:

james is from [email protected] (1st element)
admin and secretary are from [email protected] and [email protected], respectively (2nd element)
staff is from [email protected] (3rd element) and so on.
email as object keys are dynamic, meaning it can be "[email protected]", "[email protected]", etc.

I have tried, but yet not successful :

for (let i = 0; i < data.length; i++) {
  let keys = Object.keys(data[i]);
  console.log(`key-${i+1} :`, keys); // [ 'date', 'count', '[email protected]', '[email protected]' ]
  
  let emails = keys.filter(index => index.includes("@"));
  console.log(`email-${i+1} :`, emails); // [ '[email protected]', '[email protected]' ]
  
  let nameList = [];
  for (let i = 0; i < emails.length; i++) {
    let name = emails[i].split("@")[0];
    nameList.push(name);
  }
  console.log(`name-${i+1} :`, nameList); // [ 'admin', 'secretary' ]
}

Thanks in advance.

adiga · Accepted Answer · 2022-12-20 11:28:56Z

2

You could create a function which splits the keys of the object keys at @ and creates a new object using Object.fromEntries().

Here's a snippet:

const data = [{date:"17/03/2022",count:2,"[email protected]":2},{date:"17/05/2022",count:2,"[email protected]":1,"[email protected]":1},{date:"17/07/2022",count:7,"[email protected]":7}];

const converter = o => Object.fromEntries(
  Object.entries(o).map(([k, v]) => [k.split("@")[0], v])
)

console.log(
  data.map(converter)
)

If Object.fromEntries() is not supported, you could use a simple loop through the array and then each object to create new objects like this:

const output = []

for (const o of data) {
  const updated = {}
  
  for (const key in o) {
    updated[key.split("@")[0]] = o[key]
  }
  
  output.push(updated)
}

edited Dec 20, 2022 at 11:28

answered Dec 20, 2022 at 11:20

adiga

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1 Comment

marc Over a year ago

Worked like a charm and easily understandable, much appreciated!

Aslam khan · Accepted Answer · 2022-12-21 18:14:00Z

1

Try this as short as simple:

let data = [{
    "date": "17/03/2022",
    "count": 2,
    "[email protected]": 2
  },
  {
    "date": "17/05/2022",
    "count": 2,
    "[email protected]": 1,
    "[email protected]": 1
  },
  {
    "date": "17/07/2022",
    "count": 7,
    "[email protected]": 7
  },
];
const refinedData = JSON.parse(JSON.stringify(data));
refinedData.map((el, i) => {
  Object.keys(el).map(e => {
    if(e.includes('@')){
      refinedData[i][e.slice(0, e.indexOf('@'))] = refinedData[i][e];
      delete refinedData[i][e];
    }
  })
});

console.log(data, refinedData);

Try this improvement to prevent shallow copy and let me know your thoughts.

edited Dec 21, 2022 at 18:14

answered Dec 20, 2022 at 11:36

Aslam khan

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4 Comments

marc Over a year ago

This gave the expected output, but I could not assign the data.map(...) to another variable, like : const modifiedData = data.map(...). Any advice about this? Thank you in advance.

Aslam khan Over a year ago

I have improvised the code please check and let me know your thoughts

marc Over a year ago

Does JSON.parse(JSON.stringify(data)) mean you are doing a deep copy to not modify the original data? That being said, one should do a deep copy before reassigning it to another variable? Thanks in advance.

Aslam khan Over a year ago

Yes you are right, to prevent shallow copy of nested object.

TECH FREEKS · Accepted Answer · 2022-12-20 11:17:37Z

0

Can you try using this?

for (let i = 0; i < data.length; i++) {
  let element = data[i];
  let keys = Object.keys(element);

  let emails = keys.filter(index => index.includes("@"));
  for (let j = 0; j < emails.length; j++) {
    let name = emails[j].split("@")[0];
    let value = element[emails[j]];
    Object.defineProperty(element, name, { value });
    delete element[emails[j]];
  }
}

console.log(data);

answered Dec 20, 2022 at 11:17

TECH FREEKS

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1 Comment

marc Over a year ago

Thanks, but the output missed the names, it looked like this : [ { date: '17/03/2022', total: 2 }, { date: '17/05/2022', total: 2 }, { date: '17/07/2022', total: 7 } ]

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