Top 250 Frontend Development Interview Questions and Answers

UI policy and client script are both used in ServiceNow for controlling field behavior and data on forms.

• UI policy is used to dynamically change field properties, visibility, and mandatory status based on certain conditions.

• Client script is used to a...read more

The number of windows that can be maintained under one page depends on the system's capabilities and resources.

• The number of windows that can be maintained may vary based on the operating system and hardware specifications.

• Factors such as memory, pro...read more

Error handling in React can be done using try-catch blocks, error boundaries, and handling asynchronous errors.

• Use try-catch blocks to handle synchronous errors

• Use error boundaries to catch errors in child components

• Handle asynchronous errors using p...read more

To display different colors in a table using CSS for odd and even rows, you can use the :nth-child() selector.

• Use the :nth-child(odd) selector to target odd rows and apply a specific color using the background-color property.

• Use the :nth-child(even) ...read more

Modify webpage layout using layout.xml

• Layout.xml is a file used in Magento to define the structure of a webpage

• You can modify the layout of a webpage by editing the layout.xml file

• Changes in layout.xml can include adding/removing blocks, changing blo...read more

Responsive web layout can be achieved through the use of CSS media queries and flexible grid systems.

• Use CSS media queries to adjust the layout based on screen size

• Use flexible grid systems like Bootstrap or Foundation

• Design with a mobile-first appro...read more

CSS can be integrated on a web page by linking an external CSS file, using inline styles, or embedding CSS within the HTML document.

• Link an external CSS file using the tag in the section of the HTML document.

• Use inline styles by adding the 'style' a...read more

The current version of Bootstrap is 5.1.0.

• Bootstrap 5.1.0 is the latest version as of now.

• It was released on August 19, 2021.

• Bootstrap 5 is a popular front-end framework for building responsive websites and web applications.

• It provides a wide range o...read more

The deprecated methods in ReactJS 16.8 version are findDOMNode and componentWillReceiveProps.

• findDOMNode method is replaced by useRef hook.

• componentWillReceiveProps method is replaced by getDerivedStateFromProps.

• Both methods were causing performance ...read more

Design a frontend application for a healthcare management system.

• Include user authentication for healthcare professionals and patients.

• Implement features for scheduling appointments, viewing medical records, and sending messages.

• Ensure HIPAA complian...read more

The viewport is the visible area of a web page displayed on a device's screen.

• It determines the layout and dimensions of the content on the screen.

• It can be adjusted using meta tags in the HTML head section.

• It is important for responsive design and m...read more

JSX is a syntax extension for JavaScript used with React to describe what the UI should look like.

• JSX stands for JavaScript XML

• It allows developers to write HTML-like code in JavaScript

• JSX elements are transpiled into regular JavaScript function call...read more

Use jQuery to change the background color of all ul elements to blue.

• Use the jQuery selector to select all ul elements

• Use the css() method to change the background color to blue

Yes, I have experience in both backend and frontend development.

• I have worked on backend development using languages like Java, Python, and Node.js to build APIs and handle server-side logic.

• I have experience in frontend development using technologie...read more

Pure Components in React JS are components that do not re-render unless their props have changed.

• Pure Components extend React.Component and implement shouldComponentUpdate method for shallow comparison of props and state.

• Pure Components are more effi...read more

CSS3 is the latest version of Cascading Style Sheets used for styling web pages.

• CSS3 introduces new features like animations, transitions, and gradients.

• It also includes new selectors like :nth-child() and :not().

• CSS3 supports media queries for respo...read more

Responsive design using media queries and flexible layouts to adapt frontend to different devices.

• Use media queries in CSS to apply different styles based on screen size

• Utilize responsive frameworks like Bootstrap or Foundation for pre-built responsi...read more

Props are used to pass data from parent to child components, while events are used to communicate from child to parent components.

• Props are read-only and cannot be modified by the child component

• Events are emitted using $emit() method and can be list...read more

To handle drop-down, identify the element, select the option, and verify the selection.

• Identify the drop-down element using locators like ID, class, or XPath.

• Use Selenium's Select class to select the desired option.

• Verify the selection using assertio...read more

Create a page that moves

• Use CSS animations or transitions to create movement

• Consider using JavaScript for more complex animations

• Experiment with different types of movement such as sliding, fading, or rotating

DOM stands for Document Object Model, a programming interface for web documents.

• DOM is a tree-like structure that represents the HTML elements of a webpage.

• It allows developers to manipulate the content, structure, and style of a webpage using script...read more

Window load refers to the time it takes for a webpage to fully load all its content.

• It is a measure of the time it takes for a webpage to load completely

• It includes all the resources on the page such as images, scripts, and stylesheets

• A slow window l...read more

Achieve responsiveness in web page by using media queries, flexible layouts, and fluid images.

• Use CSS media queries to apply different styles based on screen size

• Create flexible layouts using CSS Grid or Flexbox

• Use relative units like percentages and...read more

A dynamic page can be created by using HTML, CSS, and JavaScript to add interactive elements and update content dynamically.

• Use HTML to structure the page and define the content.

• Apply CSS to style the page and make it visually appealing.

• Utilize JavaS...read more

Large data on front end can be managed by implementing pagination, lazy loading, virtual scrolling, and data caching.

• Implement pagination to display data in smaller chunks, reducing load time and improving performance.

• Use lazy loading to only load da...read more

Minification is the process of removing unnecessary characters from code without affecting its functionality.

• Minification reduces file size by removing comments, whitespace, and renaming variables.

• It helps improve website loading speed and performanc...read more

Reflow is a process of melting and re-solidifying solder paste to create a permanent bond between components and PCB.

• Reflow is a critical step in surface mount technology (SMT) assembly.

• It involves heating the PCB and components to a specific tempera...read more