JavaScript How to delete key from copied object? [duplicate]

Answer 1

It's because q and duplicateQ refer to the same object. Thus, when you delete a property on one object, it effects both (since they both point to the same object).

You need to copy/clone the object.

In ES6, you can use the .assign() method:

var q = {age:10, 'profile.contry': 'india'};
var duplicateQ = Object.assign({}, q);
delete duplicateQ['profile.contry'];

Output:

console.log(q);
// {age: 10, profile.contry: "india"}

console.log(duplicateQ);
// Object {age: 10}