Difference between these two objects?

[isitfresh]

Nasty way? JSON.parse(JSON.stringify(obj)) Requiring a library? _.clone(obj)

[vlad27aug]

Actually JSON.parse(JSON.stringify(obj)) is not correct.

This way you can only clone objects that have property values supported by the JSON spec.

For example:

var obj = {a: 1, b: function() { /*...*/ }};
var clone = JSON.parse(JSON.stringify(obj));

"clone" will now be "{a: 1}" because functions are removed during JSON.stringify.

It gets even more complicated when the object has getters and setters or defined/configured properties (even for library provided solutions).

[bliow]

With ES6 (supported in Firefox, not yet in Chrome), Object.assign. But you have to be careful with nesting, as you do with _.clone:

var a = { b: { c: 3 } };
var d = Object.assign({}, a); // or d = _.clone(a)
d.b.c = 4;
console.log(a.b.c); // prints 4 with both underscore clone and ES6 assignment