noun

JS

jay-ESS

JS (noun) means JavaScript, the programming language that runs in web browsers to make pages interactive, and on servers through runtimes such as Node. Example: “The whole front end is written in JS.”

noun

JavaScript, the programming language that runs in web browsers to make pages interactive, and on servers through runtimes such as Node.

"The whole front end is written in JS."

"Disable JS and half the site stops working."

The .js file extension, marking a file that contains JavaScript code.

"Put the helper functions in utils.js."

"The bundler spits out a single minified JS file."

How to Use JS

Learner’s notes

In plain EnglishShort for JavaScript, the code that makes web pages do things.

When to use it

Informal shorthand among developers; write JavaScript in full in formal documentation.

Memory tip

Say the letters, jay-ess. It takes no article when naming the language: 'written in JS', not 'in the JS'.

Trace the full origin ↓

Easily confused with

JS vs Java JS vs TS JS vs JSON

Common pairings

vanilla JS JS bundle JS framework plain JS

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The whole front end is written in _____.

Etymology

An initialism of JavaScript.

Origin: English

Synonyms

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JavaScript ECMAScript

Related Words

JavaScript

Frequently Asked Questions

What is the difference between JS and Java?

They are unrelated languages that share part of a name for historical marketing reasons. JavaScript runs in browsers and on Node servers and is dynamically typed; Java is a separate, statically typed language usually compiled to run on the Java Virtual Machine.

What is the difference between JS and TS?

TS is TypeScript, which is JavaScript plus a static type system. TypeScript compiles down to plain JavaScript, so anything written in TS ends up running as JS.

Is JS the same as ECMAScript?

Effectively yes in everyday use. ECMAScript is the formal standard the language is defined by, and JavaScript is the name of the implementations that follow it, which is why versions get called ES6 or ES2020.

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