10+ ABResh Events Interview Questions and Answers

Web storages include local storage, session storage, and cookies. Session storage is not available in other tabs or windows.

• Local storage persists even after the browser is closed, while session storage is cleared when the session ends.

• Cookies are used for storing small amounts of data that can be accessed by both the server and client.

• Session storage is only available within the same tab or window where it was created.

• Example: A user logs into a website and their login infor...read more

Polyfill is a code that provides modern functionality on older browsers.

• Polyfills are used to fill the gap between modern and older browsers.

• They are written in JavaScript and provide functionality that is not natively supported by the browser.

• Polyfills can be used for Array methods like forEach, map, filter, reduce, etc.

• Here's an example of a polyfill for the Array.prototype.forEach method: Array.prototype.forEach = function(callback) { for (var i = 0; i < this.length; i++) ...read more

Use React.memo, useCallback, and shouldComponentUpdate to reduce unnecessary re-renders.

• Use React.memo to memoize functional components and prevent re-renders when props don't change.

• Use useCallback to memoize functions and prevent re-creation on every render.

• Use shouldComponentUpdate to prevent class components from re-rendering unnecessarily.

• Avoid using inline functions in render methods as they create new function instances on every render.

• Use PureComponent instead of Comp...read more

Event bubbling and capturing are two ways of propagating events in the DOM tree.

• Event bubbling is the process of an event propagating from the innermost element to the outermost element in the DOM tree.

• Event capturing is the opposite of event bubbling, where the event is captured at the outermost element and propagated to the innermost element.

• Event listeners can be added to either the capturing or bubbling phase using the addEventListener method.

• Event.stopPropagation() can b...read more

To add custom headers to an Axios call, use the headers property in the config object.

• Create a config object with the headers property

• Pass the config object as the second argument to the Axios call

• Example: axios.get(url, { headers: { 'Authorization': 'Bearer token' } })

IndexDB is a client-side storage system for web applications.

• It allows storing data in key-value pairs.

• It is an alternative to cookies and local storage.

• It supports transactions for atomic operations.

• It can store large amounts of structured data.

• It can be accessed using JavaScript APIs.

Program to remove duplicates from an array

• Create a new empty array

• Loop through the original array and check if the element already exists in the new array

• If not, add it to the new array

• Return the new array

Web sockets are a communication protocol that allows real-time bidirectional communication between a client and a server.

• Web sockets use a persistent connection between the client and server

• They allow for real-time data transfer without the need for constant HTTP requests

• Web sockets are commonly used in chat applications, online gaming, and stock trading platforms

Prototype Inheritance is a way of creating objects based on existing objects.

• It allows objects to inherit properties and methods from other objects.

• It is a feature of object-oriented programming in JavaScript.

• It helps in creating efficient and reusable code.

• Example: A 'Car' object can inherit properties and methods from a 'Vehicle' object.

Python code to arrange non zero and negative integers in a list

• Iterate through the list and separate non zero and negative integers

• Sort the non zero and negative integers separately

• Combine the sorted lists to get the final result

Memory management is the process of controlling and coordinating computer memory, assigning portions called blocks to various programs.

• Memory management involves allocating memory to programs when needed and freeing up memory when no longer needed.

• It helps prevent memory leaks and optimize memory usage.

• Common memory management techniques include garbage collection, manual memory management, and automatic memory management.

• Examples include malloc and free functions in C, and g...read more

UITableViews are a type of view in iOS development used to display data in a scrollable list format.

• UITableViews are commonly used in iOS apps to display lists of data, such as contacts, messages, or settings.

• They consist of rows and sections, with each row representing an item of data.

• UITableViews can be customized with different cell types, styles, and layouts.

• They support features like scrolling, selection, editing, and reordering of rows.

• UITableViews are often populated w...read more

Lazy variable is a variable that is not evaluated until it is needed.

• Lazy variables are used to defer the initialization of a variable until it is actually accessed or needed.

• They can help improve performance by avoiding unnecessary computations.

• Lazy variables are commonly used in functional programming languages like Swift and Kotlin.

CocoaPods is a dependency manager for Swift and Objective-C projects.

• CocoaPods is used to easily manage and install third-party libraries in iOS projects.

• It uses a Podfile to specify project dependencies and automatically downloads and integrates them.

• CocoaPods simplifies the process of adding and updating libraries in Xcode projects.

• Example: 'pod 'Alamofire'' adds the Alamofire networking library to a project.