juniorJavaScript
What are closures in JavaScript?
Updated May 6, 2026
Short answer
A closure is a function that remembers its lexical scope.
Deep explanation
Closures allow inner functions to access outer function variables even after execution.
Real-world example
Used in data encapsulation and private variables.
Common mistakes
- Thinking closures only exist in async code.
Follow-up questions
- Where are closures used?
- Do closures consume memory?