How to remove object properties if exist on another object in Javascript / Typescript

Question

I have this object:

{
  "id": "33343232",
  "createdAt": "2022-07-26T13:44:01.080Z",
  "updatedAt": "2022-07-26T13:45:31.000Z",
  "name": "Name Here",
  "description": "text",
}

and another object is :

specificFeatures": {
    "id": "33343232",
    "createdAt": "2022-07-26T13:44:01.087Z",
    "updatedAt": "2022-07-26T13:45:31.000Z",
    "name": "Name Here",
    "description": "text",
    "coverage": "international",
    "income": 0,
    "observationIncome": "",
}

now, I want the property keys of the specificFeatures object that are the same as the first object to be deleted.

In this example, it would be:

specificFeatures": {
    "coverage": "international",
    "income": 0,
    "observationIncome": "",
}

Can you tell me how can I do this?

Answer 1

To achieve that, you can simply iterate over the object properties, check whether the "original" object has the property, and if so, delete it from "specificFeatures" object:

const original = {
  "id": "33343232",
  "createdAt": "2022-07-26T13:44:01.080Z",
  "updatedAt": "2022-07-26T13:45:31.000Z",
  "name": "Name Here",
  "description": "text",
}

const specificFeatures = {
  "id": "33343232",
  "createdAt": "2022-07-26T13:44:01.087Z",
  "updatedAt": "2022-07-26T13:45:31.000Z",
  "name": "Name Here",
  "description": "text",
  "coverage": "international",
  "income": 0,
  "observationIncome": "",
}

// Iterate over object keys
Object.keys(specificFeatures).forEach(prop => {
  // Check if the "original" object has the property defined
  if (original.hasOwnProperty(prop)) {
    // Delete the property from the "specificFeatures" object
    delete specificFeatures[prop];
  }
});

console.log(specificFeatures);

Pay attention that this way you mutate the original object, and in case you need to keep the original object as is, a new unique copy should be created. One of the possible solutions could be a combination of Object.entries() and Array.reduce() methods:

const original = {
  "id": "33343232",
  "createdAt": "2022-07-26T13:44:01.080Z",
  "updatedAt": "2022-07-26T13:45:31.000Z",
  "name": "Name Here",
  "description": "text",
}

const specificFeatures = {
  "id": "33343232",
  "createdAt": "2022-07-26T13:44:01.087Z",
  "updatedAt": "2022-07-26T13:45:31.000Z",
  "name": "Name Here",
  "description": "text",
  "coverage": "international",
  "income": 0,
  "observationIncome": "",
}

const result = Object.entries(specificFeatures).reduce((acc, [key, val]) => {
  if (!original.hasOwnProperty(key))
    acc[key] = val;
  return acc;
}, {});

console.log(result);
console.log('Is a different object:', result !== specificFeatures);