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59 free JavaScript trivia questions with answers. JavaScript trivia for developers who want something better than 'what does typeof null return'. The quiz covers the language's history (Netscape, LiveScript, the Java marketing tie-in, the Sun and Oracle trademark), its standardisation by Ecma's TC39, the engines and runtimes that run it (SpiderMonkey, V8, JavaScriptCore, Node, Deno, Bun), the tooling and library ecosystem (npm, jQuery, React, Vue, Svelte, Next.js, Electron), and the language itself: hoisting, strict mode, NaN, template literals, BigInt, and the event loop. Fifty-nine questions run from easy (who created JavaScript?) to hard (which KDE engine did WebKit fork? which package broke the internet in March 2016?). It works as a warm-up for a dev team meeting, a round in a tech-themed pub quiz, or a way to find out how much of the ecosystem's history you actually know. Every answer was checked against Wikipedia's articles on the language, its standard, its engines, and the people and projects around it, and each question carries the sentence that supports it.
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Q 01Who created JavaScript in 1995?
Brendan Eich
Brendan Eich wrote the first version in ten days in May 1995; he went on to co-found the Firefox maker and, in 2015, the Brave browser company.
Q 02At which company was JavaScript created in 1995?
Netscape
Netscape, founded in 1994 by Jim Clark and Mosaic co-author Marc Andreessen, wanted its browser to do more than display static pages and hired a language designer in April 1995 to build a scripting language.
Q 03What was the language called when it first shipped in a browser beta in September 1995?
LiveScript
LiveScript was the name in the September 1995 beta of the 2.0 browser; the switch to JavaScript came with the official release that December, borrowing the glow of a hotter language.
Q 04JavaScript's creator was originally recruited to embed which existing language in the browser?
Scheme
Scheme, the minimalist Lisp dialect, was what the new hire had been promised he could put in the browser; management then demanded a more conventional syntax, so only first-class functions and closures survived from the Lisp idea.
Q 05In December 1995, which company jointly announced JavaScript with the browser maker in a press release?
Sun Microsystems
Sun Microsystems and the browser maker issued the joint press release on 4 December 1995, with the new name chosen to ride the publicity of Sun's other language; the creator has called it a marketing ploy.
Q 06Management wanted the syntax of the new browser scripting language to resemble which language?
Java
Java was the model: management wanted the scripting language to look like Java for a marketing tie-in, so it took the braces and keywords of Java while the semantics underneath owed more to Self and Lisp.
Q 07The core language standard is published under which document number?
ECMA-262
ECMA-262 is the standard for the language itself, first published in June 1997; ECMA-404 is JSON, ECMA-334 is C#, and ECMA-119 is the ISO 9660 CD-ROM file system.
Q 08Ecma International, the standards body behind the language, is based in which city?
Geneva
Ecma was founded in Geneva in 1961 as the European Computer Manufacturers Association and kept its headquarters there after dropping the acronym to become Ecma International in 1994.
Q 09What did Internet Explorer 3.0 call its own implementation of the language in 1996?
JScript
JScript was Microsoft's reverse-engineered dialect, shipped in Internet Explorer 3.0 in August 1996 under its own name to sidestep the trademark; the two implementations differed enough to spawn years of 'best viewed in' badges.
Q 10Which term did Jesse James Garrett coin in 2005 for loading data in the background without a full page reload?
Ajax
Ajax, short for Asynchronous JavaScript and XML, was the label in Garrett's February 2005 essay; the XMLHttpRequest object behind it had been built by Microsoft's Outlook Web Access team in the late 1990s.
Q 11Chrome shipped in 2008 with which JavaScript engine, faster than anything else at the time?
V8
V8, named after the car engine, was built in Aarhus by a team under Lars Bak and launched with Chrome on 2 September 2008, compiling JavaScript straight to machine code.
Q 12Which engine, the first ever written for the language, has powered Firefox since 2004?
SpiderMonkey
Its JIT compilers have been called TraceMonkey, JägerMonkey, IonMonkey and WarpMonkey.
Q 13Apple's WebKit began in 2001 as a fork of KHTML and which KDE JavaScript engine?
KJS
KJS, the JavaScript engine of KDE's Konqueror browser, was forked alongside KHTML when Lisa Melton started the WebKit project inside Apple on 25 June 2001, chosen over Gecko because the KDE code was small and clean.
Q 21Who created jQuery in January 2006?
John Resig
John Resig unveiled jQuery at BarCamp NYC in January 2006, influenced by Dean Edwards' cssQuery; its chainable methods and CSS-style selectors made cross-browser DOM scripting bearable.
Q 22React was created by Jordan Walke, a software engineer at which company?
Facebook engineer Jordan Walke built the first prototype, FaxJS, and React ran on the News Feed in 2011 and on Instagram in 2012 before being open-sourced.
Q 23React was officially open-sourced at a JavaScript conference in which year?
2013
2013 was the year: the library was open-sourced at JSConf US in late May 2013, two years after it first ran on the company's News Feed; React Native followed in 2015.
Q 14Node.js was created in 2009 by whom?
Ryan Dahl
Ryan Dahl wrote Node in 2009, frustrated that thread-per-connection servers such as Apache struggled past 10,000 simultaneous connections; his design used non-blocking I/O with a single thread handling callbacks.
Q 15Node's creator later co-created which runtime, announced in a 2018 talk about his regrets?
Deno
Deno, an anagram of Node, was unveiled in the 2018 talk '10 Things I Regret About Node.js'; first prototyped in Go, it was rewritten in Rust and sandboxes file and network access behind explicit permissions.
Q 16The Bun runtime, unlike Node, uses which JavaScript engine?
JavaScriptCore
JavaScriptCore, the engine from Apple's WebKit, underpins Bun; Jarred Sumner built the runtime in Zig, opened it to the public in July 2022 and shipped version 1.0 in September 2023.
Q 17Which package manager was introduced for Node.js in January 2010?
npm
npm was first published in January 2010 and bundled with Node from late 2011; its documentation insists the name is a recursive backronym for 'npm is not an acronym', not 'Node Package Manager'.
Q 18In March 2016, the unpublishing of which tiny package broke Babel, webpack and thousands of builds?
left-pad
left-pad, an 11-line function, vanished when Azer Koçulu unpublished all his modules after the registry sided with the messaging company Kik in a dispute over the name 'kik'; thousands of builds broke until it was restored.
Q 19In December 2014 Fedor Indutny forked Node.js over its governance. What was the fork called?
io.js
The fork tracked the latest V8 releases and was later merged back, with governance passing to what became the OpenJS Foundation.
Q 20Who took over management of Node.js from its founder in January 2012?
Isaac Schlueter
Isaac Schlueter, the author of the package manager bundled with Node, ran the project at Joyent from January 2012 until handing it to TJ Fontaine in January 2014; Joyent had built the native Windows port with Microsoft in 2011.
Q 24React Hooks such as useState and useEffect arrived in which version?
16.8
16.8, released in February 2019, introduced Hooks after Dan Abramov and Sophie Alpert demonstrated them at React Conf in October 2018; they let function components hold state and side effects.
Q 25Vue.js was created by which developer after he had worked at Google with AngularJS?
Evan You
Evan You, then at Google Creative Lab, began Vue to keep the parts of AngularJS he liked without the weight; it was publicly announced in February 2014 and is pronounced like 'view'.
Q 26Svelte, the framework that compiles components away at build time, was created by whom?
Rich Harris
Rich Harris released Svelte in November 2016 as the successor to his Ractive.js; its compiler turns components into plain DOM-updating code, so no framework runtime ships to the browser.
Q 27Next.js, the React framework with server-side rendering, was created by which company?
Vercel
Vercel, known as ZEIT when Guillermo Rauch released the first version on GitHub on 25 October 2016, built Next.js to add server rendering and file-based routing to React; the company renamed itself Vercel in 2020.
Q 28Which engineer originally developed AngularJS in 2009 for an online JSON storage service?
Miško Hevery
Miško Hevery and Adam Abrons built it in 2009 for GetAngular, a JSON storage service, before Hevery brought it into Google; long-term support for AngularJS ended on 31 December 2021, after the ground-up rewrite Angular had replaced it.
Q 29Ember.js got its name in December 2011 when which framework's 2.0 version was renamed?
SproutCore
SproutCore 2.0, the rewrite Yehuda Katz and Tom Dale led, was renamed Ember.js in December 2011 because it had diverged so far from the original framework; Katz later sat on TC39, the committee that steers the language.
Q 30CoffeeScript, Backbone.js and Underscore.js were all created by which developer?
Jeremy Ashkenas
Jeremy Ashkenas made his first CoffeeScript commit on 13 December 2009, labelled 'initial commit of the mystery language', having released Underscore.js earlier that year; Backbone.js followed in October 2010.