JS Practice — Built-in Objects

Symbol.keyFor() — undefined for local symbol

📖 Usage Example

const local = Symbol('local')
Symbol.keyFor(local)   // → undefined

Local symbols created with Symbol() are not in the registry, so keyFor returns undefined.

Symbol.keyFor with Local Symbol

A symbol created with Symbol() is not in the global registry, so Symbol.keyFor returns undefined.

Challenge: Verify the result is undefined.

💡 Hints (1)