JavaScript

Cross-platform mobile apps are increasingly being built with React Native. But how can you scan for QR codes and augment the user's camera view when they're present?

While components have been available in Angular since the beginning, they’re still easy to mess up with common mistakes like people not using them at all, creating components instead of attribute directives, and more. In this article, Toptal Freelance JavaScript Developer Valters Valdersteins differentiates the correct and incorrect ways to use Angular components and illustrates them with examples.

In recent years, React has established itself as the most popular library in the JavaScript universe. However, rather than rest on its laurels, the React team is still working hard to make it better. In the second part of our React tutorial series, Toptal JavaScript Developer Kamil Jakubczak takes a closer look at some of its features, including hooks, the latest addition to React.

It’s easy to start working with a spreadsheet, but it also takes time to master your skills to use all the powerful features it provides. When you start feeling comfortable with formulas, functions, pivot tables, etc., there is still one more level which allows you to achieve even more—custom extensions. In this article, I’m going to focus on extending Google Spreadsheets with a Google Apps Script that validates European Union VAT IDs via API calls.

Bulletproof data validation is fundamental to implementing a back-end API. Find out how datalize, a Node.js library, makes this easy—and formats your data nicely, too.

The React Context API was been around as an experimental feature for a while now but finally became safe to use in production last year, solving one major problem React problem — prop drilling. In this article, Toptal Freelance Javascript Developer Boris Yordanov will introduce us to the API and illustrate it with two basic web store apps, one built with the Context API and one without it.

Discord is a popular real-time messaging platform with robust support for programmable bots. Bots are ubiquitous on Discord and provide a wide range of services, including moderation assistance, games, music, internet searches, payment processing, and more. In this article, Toptal Freelance Software Engineer and Chatbot Developer Randall Schmidt discusses the Discord UI and APIs for bots and presents a Discord bot tutorial. ImBursting, the developer of Rythm—one of Discord’s most popular bots—shares his experiences on developing and maintaining his significant infrastructure and codebase.

In recent years, React went from being an also-ran in the JavaScript universe to the most popular JS library. However, how does React stack up against Angular and VueJS in 2019? In the first part of our React tutorial series, Toptal JavaScript Developer Kamil Jakubczak outlines the reasons behind React’s popularity and explains how to get started on your first React app.

Without proper state management, your Angular app will become a UX nightmare. But even with that solved, persisting state across sessions and devices can be tricky. This tutorial shows how to leapfrog that challenge using Firebase.