(2).Null vs Undefined

(3).scope, block scope

Scope to any variable in the case of your code or other determines the accessibility of the organization.

(4.)bind, call and apply

Bind (): Gives you a new function allowing you to pass an array and a number of arguments.

(5).understand the this keyword

This keyword for a function is unnecessarily different in JavaScript than in other languages. Strict mood and no strict there are also some differences in mood.

(6).setTimeout, setInterval

setTimeout(): Execute a block only once the specified time has elapsed.

(7).DOM (Document Object Model )

(8).callback function

(9).what is an API

API is an acronym for Application Programming Interface which allows the two applications to talk to each other.


A closure is a combination of connected functions associated with the lexical environment of the surrounding state.