Hello World
Writing a Node.js program is as simple as creating a new file with a .js
extension. For example you could create a simple hello_world.js
file with the following content:
console.log('Hello World!');
After you have saved the file, you can execute it from your terminal like so:
node hello_world.js
and the ouput will be
Hello World
Hello World on a server
Now printing hello world to a terminal isn’t all that exciting. Let’s take the next step and write a program that responds to hello world via http. We’ll call the file hello_server.js
and put the following code into it:
var http = require('http');
var server = http.createServer(function(req, res) {
res.writeHead(200);
res.end('Hello World, I am in the server!');
});
server.listen(8080);
Now let’s run this program from the terminal by typing:
node hello_server.js
Testing the server is as simple as opening a new browser tab, and navigating to the following url: http://localhost:8080/
. As expected, you should see a response that reads:
‘Hello World, I am in the server!’.