Discussion on: Copying objects in JavaScript

[Bernard Baker]

Great article. Many of us encounter this problem and don't know how to resolve it. I've personally encountered it once or twice.

[Rohit Kumawat]

So there is a lodash library which gives cloneDeep() method to perfectly deep copy an object. Below an example attached:

var objects = [{ 'a': 1 }, { 'b': 2 }];
var deep = _.cloneDeep(objects);

You can also visit this page to find more: lodash.com/docs/4.17.15#cloneDeep

Another approach is to use recursion.
make a custom function like one I have used to iterate on each key in object and if that key is also an object then again call the method to copy the keys.
Something like below:

function isObject(obj) {
  let type = typeof obj;
  return type === 'object';
};

function deepCopy(obj) {
  let copiedObj = {};
  for (let key in obj) {
    if (obj.hasOwnkeyerty(key)) {
      if (isObject(obj[key])) {
        copiedObj[key] = deepCopy(obj[key]);
      } else {
        copiedObj[key] = obj[key];
      }
    }
  }
  return copiedObj;
}

[abhishek gupta]

I have stopped using lodash. I will use the recursive function

[Benneth Yankey]

I surely will use the recursion approach too. However, typeof is sloppy in terms of differentiating between array and object. In order to truly check for object type, I will go with plain old trick below:

function isObject(value) {
  return Object.prototype.toString.call(value) === '[object Object]';
}

[Rohit Kumawat]

Cool. I missed that part. Thanks for the solution.

I was just giving some information about how can we make such a function to deep copying with help of recursion. So, there might be some more improvements that can be implemented to make it handle every case.

But Great Insight!

[Bernard Baker]

That's a good point.

[Bernard Baker]

I like the recursive function.

[Rohit Kumawat]

Great! make your own common function to handle all cases.

Enjoy!