Getting started with Deno

Last updated: October 25, 2023

Deno city

Deno is more secure and simpler alternative to Node.js

  • Deno focuses on security and restricts permissions by default
  • You can easily allow permissions for specific actions

Deno supports JavaScript and TypeScript

  • You can write your code in JavaScript or TypeScript
  • Deno handles TypeScript, code formatting, linting, and type checking out of the box

Deno has a built-in Key/Value store

  • Deno provides a JavaScript friendly database with a few lines of code
  • It uses SQLite in custom deployments and a cloud-based store in Deno Deploy

Deno is backwards compatible with npm packages

  • You can still use npm libraries with Deno
  • There is an --no-npm flag to avoid node_modules

Installing Deno

  • MacOS or Linux
curl -fsSL | sh
  • Windows
irm | iex

Getting started with Deno is simple

  • Open a text editor and start writing Deno apps
  • No need to install anything else
  • For example, create a hello.ts file and write:
console.log('Hello, Deno!');
// Run the program with `deno run hello.ts`.
// You'll see the output "Hello, Deno!"

Importing packages in Deno

  • Import JavaScript/TypeScript modules directly from URLs
  • Use for packages and deno-types for npm packages
  • Example
// @deno-types="npm:@types/[email protected]"
import express from 'npm:[email protected]';

const app = express();

app.get('/', (req, res) => {
  res.send('Hello Deno!');