Override an object from array of objects in javascript

Question

I have an array of object as below:

let arr = [{
    id: 1,
    name: 'John',
    lastName: 'Smith'
  },
  {
    id: 2,
    name: 'Jill',
    lastName: 'Smith'
  }
];

I want to update an object with id = 1 with some properties from another object.

const obj = {
  id: 1,
  name: 'JOHn1'
}

The expected out is:

[{
    id: 1,
    name: 'JOHn1',
    lastName: 'Smith'
  },
  {
    id: 2,
    name: 'Jill',
    lastName: 'Smith'
  }
]

I tried using Object.assign(), but it does not work. Could anyone please let me know.

arr = Object.assign(arr, obj);

thanks

Terry · Accepted Answer · 2022-10-11 11:11:24Z

1

You need to find the entry which you want to use as the assign target first: in this case, you need to query for the entry where id is 1. This can be done by using Array.prototype.find to locate the target, and then do Object.assign() on the target itself.

Since the found object is pass-by-reference, updating the object directly will update its entry in your array of objects directly.

See proof-of-concept below:

const arr = [{
    id: 1,
    name: 'John',
    lastName: 'Smith'
  },
  {
    id: 2,
    name: 'Jill',
    lastName: 'Smith'
  }
];

const obj = {
  id: 1,
  name: 'JOHn1'
};

const foundObj = arr.find(({ id }) => id === obj.id);
if (foundObj) {
  Object.assign(foundObj, obj);
}

console.log(arr);

answered Oct 11, 2022 at 11:11

Terry

66.7k16 gold badges107 silver badges127 bronze badges

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

Collectives™ on Stack Overflow

Override an object from array of objects in javascript

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related