# What Is JavaScript Made Of?

DevFeed: [What Is JavaScript Made Of?](<https://devfeed.tech/articles/what-is-javascript-made-of-36206.md>)

Original publisher: [Read original article](<https://overreacted.io/what-is-javascript-made-of/>)

Published: 2019-12-20T00:00:00Z

Content type: tutorial

Language: en

Sources: [Dan Abramov](<https://devfeed.tech/sources/dan-abramov.md>)

Topics: [JavaScript](<https://devfeed.tech/topics/javascript.md>), [Web Development](<https://devfeed.tech/topics/web-development.md>)

Tags: [fundamentals](<https://devfeed.tech/tags/fundamentals.md>), [javascript](<https://devfeed.tech/tags/javascript.md>)

## AI overview

A concise glossary-style introduction to JavaScript fundamentals, covering values, value types, primitive values, missing values, and equality. The article aims to help readers build a stronger mental model of JavaScript.

## Source excerpt

Getting a closure on JavaScript.