Start your text editor of choice and create a file named app.js. I strongly encourage the use of Express.ĥ.
Express has become so popular, it now is the de facto standard, in the vast majority of Node.js applications today. It gives you a set of robust and easy to use tools to get your web application up and running. “Fast, unopinionated, minimalist web framework for Node.js” - Taken from Express.js’ official website What exactly is this Express thing? Some mail delivery service, rivaling FedEx, I presume (please ignore these lame jokes). The addition of -save will save the package to your dependencies list, located in the package.json, in your myapp directory. This is a crucial step, as you will be able to require any of the recently installed files in your own application files. You will now be able to see a node_modules folder get created in the root of your project. The install command will go ahead and find the package you wish to install, and install it to your project. While still in the myapp directory run: npm install express -save There are 6 simple steps in this example, bear with me. Upon each connection the callback is fired, but if there is no work to be done Node will remain asleep. In the following “Hello World” example, many connections can be handled concurrently. Node is based on this non-blocking execution, making it one of the fastest tools for building web applications today. This is what asynchronous means, handling events without interrupting the main thread. So you don’t want events to interrupt the main thread of execution. JavaScript is single threaded, meaning there is only one thread of execution. Regarding the definition, you might be wondering what the term asynchronous even means in the current context. So what do we have now? A way to write JavaScript on the back end.
It’s an environment where the language can get interpreted. Don’t get confused with the word runtime. The creator of Node.js took Chrome’s engine and built a runtime for it to work on a server. The browser’s engine takes JavaScript code and compiles it into commands. You may now be wondering, how? As you know, JavaScript is a language which runs in a browser. Node.js enables you to write server side JavaScript. That being the raw definition, let me clarify. It’s designed to build scalable network applications. Node is an asynchronous event driven JavaScript runtime built upon Chrome’s V8 JavaScript engine.
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