IK Interview Knowledge Book

Topics Practice Examples Playground

RU

Computer Science and Algorithms 4
JavaScript Core 8
TypeScript 4
HTML, CSS, and Browser Platform 3
Frontend Frameworks 4
Node.js, APIs, and Security 6
Testing, Design, and Architecture 9
System Design and Data 2
- Databases and Storage 9
- ORM and Data Access 6
Tooling, Platform, and Process 10

JavaScript Core Scope and execution

foundation

Scope and execution

Lexical environments, hoisting, bindings, closures, this, and function invocation.

Practice for this topic

What does a closure preserve?What happens when this code runs?What does this program print?Which call succeeds before the function line in the same scope?

Runnable examples

Closure-backed private counter