The following are 15 frequently asked frontend developer interview questions and answers, which candidates can quickly review and prepare for an interview round.
1. What is Web Application?
ANS: A web application is a program that uses web and web browser technologies to accomplish one or more tasks over a network, typically via a web browser.
2. What is A JavaScript Object?
ANS: It is a collection of data that includes both methods and properties. A document's elements are all objects. You can obtain each of these objects by using the DOM.
3. What skills do you need to be a frontend developer?
ANS: The skills required to be a frontend developer are:
- JQuery
- CSS
- HTML
- JavaScript
4. What is Event Delegation?
ANS: You can avoid adding event listeners for specific nodes by using Event Delegation. Instead, a single event listener can be added to a parent element.
5. Describe Coffee Script?
ANS: CoffeeScript is a small programming language that can be compiled into JavaScript. It is an attempt to demonstrate the best features of JavaScript in a straightforward manner. It also helps you write better JavaScript code by providing a more consistent syntax and avoiding the unusual nature of the JavaScript language.
6. What is a callback function?
ANS: To prevent this from happening, a callback function is used, which is not called until the previous line of code has been fully executed.
7. Explain what is the difference between a host object and a native object?
ANS: Host Objects - are objects that are provided by a specific environment.
Native Objects - are Javascript's standard built-in objects.
8. Can you tell us when you'd use CSS clear?
ANS: Clear can be used when I don't want an element on the left or right of the floating element to wrap around it.
9. Explain the difference between cookies, session storage, and local storage?
ANS: Cookies enable applications to store data in the browser of a client.
Applications can use the session storage property to store data until the window is closed.
The local storage property allows applications to store data indefinitely.
10. What is Ajax?
ANS: AJAX (Asynchronous JavaScript and XML) allows applications to send and receive data asynchronously from and from a server without refreshing the page. This means that it is possible to update parts of a web page without having to reload the entire page. For example, even if you haven't refreshed the web page, new Gmail messages arrive and are marked as such.
11. What is Event Bubbling?
ANS: Event bubbling is a type of event propagation in which the event occurs first on the deepest target element. It causes all events in the child nodes to be passed to the parent nodes automatically. This method is faster because the code only needs to traverse the DOM tree once.
12. Explain the difference between classes and IDs?
ANS: Both classes and ID selectors are used as CSS-style hooks. The IDs are frequently used to style components that appear only once on a page, such as a navigational menu. Classes are used to style various elements in a consistent manner, such as the existence of links.
13. Can you tell us when would you utilize CSS float?
ANS: When you need to make an element of your web page float to the right or left and have other elements wrap around it, you use float.
14. Explain how you'd go about making sure your website is user-friendly, and what actions you'd take?
ANS: Working with UX (User Experience) designers to imagine and conceptualize a web page that cultivates a user-centric experience, testing the website with users to ensure optimal design, and ensuring the web page is optimized for mobile phone viewing are all topics that a front-end developer should discuss.
15. How do you organize your source code such that other coworkers may easily use it?
ANS: A front-end developer should talk about how they organize their code and comment on it. They must explain how they use notes in their programming process to explain the actions they've done, ensuring that all collaborators are on the same page.
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