Which company originally created React?
AnswerFacebook (Meta)
React was created at Facebook and open-sourced in 2013.
Coding · Facts & stats
React facts & stats
7 fact-checked facts about the react javascript library for building user interfaces, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
What syntax lets you write HTML-like code in React?
AnswerJSX
JSX is a JavaScript syntax extension.
Going deeper
Which hook adds state to a function component?
AnsweruseState
useState returns a value and a setter.
Which hook runs side effects, like fetching data?
AnsweruseEffect
useEffect runs after render for side effects.
In what year was React open-sourced?
Answer2013
React was released publicly in May 2013.
Expert level
What is the in-memory representation React uses to compute UI changes?
AnswerVirtual DOM
React diffs a virtual tree to minimize real DOM updates.
What is React Native?
AnswerReact for building native mobile apps
React Native uses React to build iOS and Android apps.
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