Javascript interview questions

Basic JS programmming

Scope of variable
What is Associative Array? How do we use it?
OOPS JS

Difference between Classic Inheritance and Prototypical Inheritance
What is difference between private variable, public variable and static variable? How we achieve this in JS?
How to add/remove properties to object in run time?
How to achieve inheritance ?
How to extend built-in objects?
Why extending array is bad idea?
DOM and JS

Difference between browser detection and feature detection
DOM Event Propagation
Event Delegation
Event bubbling V/s Event Capturing
Misc

Graceful Degradation V/s Progressive Enhancement