What are the ways to copy an object in JavaScript?

In JavaScript, there are several ways to copy objects:

1. Shallow copy:

   • Object.assign({}, obj) — copies only the top level of properties.
   • Spread operator: { ...obj } — also a shallow copy.

2. Deep copy:

   • JSON.parse(JSON.stringify(obj)) — a simple method, but does not copy functions, dates, undefined, etc.
   • Recursive function for deep copying.
   • Using specialized libraries, e.g., lodash.cloneDeep.

Example of shallow copy:

const original = { a: 1, b: { c: 2 } };
const copy = { ...original };
copy.b.c = 3;
console.log(original.b.c); // 3 — changed because it is a shallow copy

Example of deep copy with JSON:

const original = { a: 1, b: { c: 2 } };
const deepCopy = JSON.parse(JSON.stringify(original));
deepCopy.b.c = 3;
console.log(original.b.c); // 2 — original remains unchanged