Q23: What is the difference between a Shallow Copy and a Deep Copy?
A shallow copy (Object.assign(), {...obj}) copies top-level properties, but nested objects/arrays retain memory references. A deep copy (structuredClone(), JSON.parse(JSON.stringify())) recursively duplicates all nested structures, creating completely independent object graphs.
Key Takeaways
- Shallow copy leaves nested objects linked by reference.
- Deep copy duplicates all nested layers independently.
Knowledge Check
Which modern native JavaScript global function performs deep copying safely?