JavaScript

JavaScript syntax, DOM, ES6+, async patterns, and web interactivity.

Quizzes

Questions

eBooks

Articles

Likes

Views

More topics in Computer Science

All

Computer Science

AJAX

00 Quizzes

Angular JS

00 Quizzes

ASP .NET

00 Quizzes

Bootstrap

00 Quizzes

C

00 Quizzes

C#

00 Quizzes

C++

00 Quizzes

CodeIgniter

00 Quizzes

Computer Networks

01 Quizzes

CSS

01 Quizzes

Data Structures & Algorithms

02 Quizzes

Databases

01 Quizzes

Go Lang

00 Quizzes

HTML

01 Quizzes

Java

00 Quizzes

JavaScript

01 Quizzes

JQuery

00 Quizzes

Laravel

00 Quizzes

Node JS

00 Quizzes

Operating Systems

01 Quizzes

PHP

00 Quizzes

Python

01 Quizzes

React JS

00 Quizzes

React Native

00 Quizzes

Ruby on Rails

00 Quizzes

Software Engineering

01 Quizzes

Tailwind CSS

00 Quizzes

Vue JS

00 Quizzes

Explore

QUESTION NO 01

Which keyword declares a block-scoped variable?

Answer: let

let (and const) are block-scoped; var is function-scoped.

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

QUESTION NO 02

JavaScript is primarily used for?

Answer: Making web pages interactive

JS adds behavior and interactivity in browsers (and servers via Node).

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

QUESTION NO 03

=== compares?

Answer: Value and type

Strict equality checks type and value without coercion.

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

QUESTION NO 04

typeof null returns?

Answer: "object"

A long-standing JS quirk: typeof null === "object".

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

QUESTION NO 05

Array method that creates a new array by transforming each item?

Answer: map

map returns a new array of mapped values.

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

QUESTION NO 06

JSON stands for?

Answer: JavaScript Object Notation

JSON is a text format based on JS object syntax for data interchange.

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

QUESTION NO 07

A Promise represents?

Answer: A future completion/failure of an async operation

Promises handle asynchronous success (resolve) or failure (reject).

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

QUESTION NO 08

addEventListener is used to?

Answer: Attach event handlers to elements

It registers callbacks for events like click, submit, keydown.

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

QUESTION NO 09

const prevents?

Answer: Reassignment of the binding

const forbids reassigning the variable; object contents may still change.

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

QUESTION NO 10

NaN stands for?

Answer: Not a Number

NaN is the result of invalid numeric operations; typeof NaN is "number".

Shahzad Mahota @shahzad-mahota

302 Quizzes

2930 Questions

00 Likes

JavaScript

More topics in Computer Science

All

AJAX

Angular JS

ASP .NET

Bootstrap

C

C#

C++

CodeIgniter

Computer Networks

CSS

Data Structures & Algorithms

Databases

Go Lang

HTML

Java

JavaScript

JQuery

Laravel

Node JS

Operating Systems

PHP

Python

React JS

React Native

Ruby on Rails

Software Engineering

Tailwind CSS

Vue JS

Explore

Which keyword declares a block-scoped variable?

Explanation

JavaScript is primarily used for?

Explanation

=== compares?

Explanation

typeof null returns?

Explanation

Array method that creates a new array by transforming each item?

Explanation

JSON stands for?

Explanation

A Promise represents?

Explanation

addEventListener is used to?

Explanation

const prevents?

Explanation

NaN stands for?

Explanation