Object.assign keeps reference to original object

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How do I correctly clone a JavaScript object? 54 answers

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In fact this can be done in different ways:

Implement you own if you don't want external import, but take in consideration nested object. I implemented my own as follow (in case you have a nested object you need deep clone, so set deep=true ):

function cloneObj(obj, deep=false){
  var result = {};
  for(key in obj){
    if(deep && obj[key] instanceof Object){
       if(obj[key] instanceof Array){
         result[key] = [];
         obj[key].forEach(function(item){
            if(item instanceof Object){
               result[key].push(cloneObj(item, true));
            } else {
               result[key].push(item);
            }
         });
       } else {
         result[key] = cloneObj(obj[key]);
       }
    } else {
       result[key] = obj[key];
    }
  }
  return result
}


// Shallow copy
var newObject = cloneObj(oldObject);
// Deep copy
var newObject = cloneObj(oldObject, true);

use jQuery :

// Shallow copy
var newObject = jQuery.extend({}, oldObject);

// Deep copy
var newObject = jQuery.extend(true, {}, oldObject);

using UnderscoreJS:

 // Shallow copy
 var newObject = _.clone(oldObject);

PS: I tested my function with the following data and works fine:

var oldObject = {a:1, b:{d:2,c:6}, c:[1,2,{t:1}]};
newObject= cloneObj(oldObject, true);

newObject['b']['d']=8;
newObject['a']=8;
newObject['c'][2]['t']=5;


console.log(oldObject)
console.log(newObject)

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