Technical interview questions and answers are extremely important for JavaScript Interviews because JavaScript powers most modern web applications. Companies evaluate your understanding of functions, scope, closures, events, DOM manipulation, ES6 features, promises, async/await, and real-time coding skills. JavaScript is one of the most commonly tested subjects in frontend developer interviews, full-stack roles, and placement assessments. Companies like TCS, Infosys, Wipro, Cognizant, and Accenture frequently include JavaScript questions in their technical rounds. This guide covers the most frequently asked JavaScript interview questions with detailed explanations to help freshers and job seekers prepare effectively. Learning these questions will give you confidence during coding tests, practical tasks, and web development interviews.
Frontend developers should enhance their skills by mastering CSS styling techniques and HTML structure fundamentals
Showing 10 of 78 questions
31. Are Java and JavaScript the Same?
No.java and javascript are two different languages.
Java is a powerful object - oriented programming language like C++,C whereas Javascript is a client-side scripting language with some limitations.
32. How to embed javascript in a web page?
javascript code can be embedded in a web page between tags
33. What and where are the best JavaScript resources on the Web?
The Web has several FAQ areas on JavaScript. The best place to start is something called the meta-FAQ [14-Jan-2001 Editor's Note: I can't point to it anymore, it is broken!], which provides a high-level overview of the JavaScript help available on the Net. As for fact-filled FAQs, I recommend one maintained by Martin Webb and a mini-FAQ that I maintain.
For interactive help with specific problems, nothing beats the primary JavaScript Usenet newsgroup, comp.lang.javascript. Depending on my work
34. What is the difference between a web-garden and a web-farm?
Web-garden - An IIS6.0 feature where you can configure an application pool as a web-garden and also specify the number of worker processes for that pool. It can help improve performance in some cases.
Web-farm - a general term referring to a cluster of physically separate machines, each running a web-server for scalability and performance (contrast this with web-garden which refers to multiple processes on one single physical machine).
35. How to get the contents of an input box using Javascript?
Use the "value" property.
var myValue = window.document.getElementById("MyTextBox").value;
36. How to determine the state of a checkbox using Javascript?
var checkedP = window.document.getElementById("myCheckBox").checked;
37. How to set the focus in an element using Javascript?
38. How to access an external javascript file that is stored externally and not embedded?
This can be achieved by using the following tag between head tags or between body tags.
How to access an external javascript file that is stored externally and not embedded? where abc.js is the external javscript file to be accessed.
39. What is the difference between an alert box and a confirmation box?
An alert box displays only one button which is the OK button whereas the Confirm box displays two buttons namely OK and cancel.
40. What is a prompt box?
A prompt box allows the user to enter input by providing a text box.