noun

JavaScript

JAH-vuh-skript

JavaScript (noun) means a programming language that runs inside a web browser and makes pages do things — respond to clicks, update without reloading, validate what you type, animate elements. It also runs on servers and other devices. Example: “The dropdown menu is written in JavaScript, so it will not open if scripts are blocked.”

noun

technical A programming language that runs inside a web browser and makes pages do things — respond to clicks, update without reloading, validate what you type, animate elements. It also runs on servers and other devices.

"The dropdown menu is written in JavaScript, so it will not open if scripts are blocked."

"He is learning JavaScript before touching any of the bigger frameworks."

How to Use JavaScript

Learner’s notes

In plain EnglishJavaScript is the code that makes a web page actually do things when you use it.

When to use it

Abbreviated JS in everyday developer speech and in filenames (.js). Capitalised with an internal capital S.

Memory tip

JavaScript and Java are separate, unrelated languages with different designers, different syntax and different uses. The similar name is a marketing decision from the 1990s, not a family relationship.

Trace the full origin ↓

Easily confused with

Java → JSON → TypeScript ECMAScript

Common pairings

vanilla JavaScript JavaScript framework client-side JavaScript disable JavaScript JavaScript engine

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Fill the Gap

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The dropdown menu is written in _____, so it will not open if scripts are blocked.

Etymology

From Java, the name of an unrelated programming language, plus script. The language was originally released under a different name and renamed to JavaScript for its launch.

Origin: English

Synonyms

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JS ECMAScript

Related Words

Frequently Asked Questions

What is the difference between Java and JavaScript?

They are entirely different languages that happen to share part of a name. Java is a general-purpose language usually compiled and run on a virtual machine, common in enterprise systems and Android apps; JavaScript was built for web browsers and runs directly in them. Knowing one does not mean you can read the other.

What is the difference between HTML, CSS and JavaScript?

HTML is the content and structure of a page, CSS is how it looks, and JavaScript is what it does. A page can exist with only HTML; CSS and JavaScript are layered on top for appearance and behaviour.

Is JavaScript the same as ECMAScript?

ECMAScript is the formal standard that defines the language, and JavaScript is the name almost everyone uses for the language itself. In practice the terms are used interchangeably, though version numbers such as ES2015 refer to the standard.