Book Image

Deno Web Development

By : Alexandre Portela dos Santos
Book Image

Deno Web Development

By: Alexandre Portela dos Santos

Overview of this book

Deno is a JavaScript and TypeScript runtime with secure defaults and a great developer experience. With Deno Web Development, you'll learn all about Deno's primitives, its principles, and how you can use them to build real-world applications. The book is divided into three main sections: an introduction to Deno, building an API from scratch, and testing and deploying a Deno application. The book starts by getting you up to speed with Deno's runtime and the reason why it was developed. You'll explore some of the concepts introduced by Node, why many of them transitioned into Deno, and why new features were introduced. After understanding Deno and why it was created, you will start to experiment with Deno, exploring the toolchain and writing simple scripts and CLI applications. As you progress to the second section, you will create a simple web application and then add more features to it. This application will evolve from a simple 'hello world' API to a web application connected to the database, with users, authentication, and a JavaScript client. In the third section, the book will take you through topics such as dependency management, configuration and testing, finishing with an application deployed in a cloud environment. By the end of this web development book, you will become comfortable with using Deno to create, maintain, and deploy secure and reliable web applications.
Table of Contents (15 chapters)
Section 1: Getting Familiar with Deno
Section 2: Building an Application
Section 3: Testing and Deploying

Hello World

With everything in place, let's write our first program!

First, we need to create a file named my-first-deno-program.js and write something that we're familiar with. We'll use the console API to write a message to the console:

console.log('Hello from deno');

To execute this, let's use the CLI we installed in the previous section. The command we must use to execute programs is called run:

$ deno run my-first-deno-program.js
Hello from deno


All Deno CLI commands can be executed with the --help flag, which will detail all the command's possible behaviors.

At this point, we haven't really done anything we don't know what to do already. We just wrote a console.log file in the language that we're familiar with, JavaScript.

The interesting thing is that we learned how to execute programs by using the run command. We'll explore this in more detail later in this chapter.


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