Functions

Functions are basically a way of making sure the program can multitask. For example, it allows asynchronous tasking, making it so that many people can connect to a website at the same time.

Modules are a way of sharing data to other scripts. When you want to send data to the main script in your program, you would use

module.exports = {

    sayHello: function(){ return "Hello"; }

    sayGoodbye: function(){ return "Goodbye.";}

}

Modules

fs.readFile('input.txt', function (err, data) {
    if (err) return console.error(err);
    console.log(data.toString());
});
the bolded text is a function.

Variables

Variables are for storing data for later use. It is also used to access downloaded modules. You can store strings of text, or a function from another file with module.exports.

var lel = "Vikstar123"

var sio = require('socket.io')

Events

Events are used like functions. They wait for something to happen like a webpage sending data to the server. I made an example that will be shown later.

  socket.on('addpepl', function (data) {
    fs.appendFile(pblc + '\\ppl.txt', data + "<br>", (err) => {
      if (err) throw err;
      console.log(data + "has been added to "+pblc+"\\ppl.txt");
    });
  }); //Event is in bold

NPM stands for Node Package Manager. It is a database for every packages you can download. It is a little complicated, but if you use NPM, you don't have to worry about having to downloading all of the files manually.

npm init

npm install -save express socket.io

Packages are third party modules downloaded and installed to make writing a program easier. When people have already made something, others use it, don't they?

Packages