Let's build a Module

• You should give your application an entry point, it usually is APP.js
• Then you load the module with require

How require and module really work?

• When run with debugger, on the left is the variables that are available to you
• this is set up to your by ECMA standard
• But what is module and exports object?
• We will find this out in the next chapter

APP.js

// ./means what we require is in the same folder as this file sitting
// we use require to get our first module



var greet = require('./greet.js');

// now you can call greet() now that are in other module
// you did it on porpose, not moduel accidentlly impact other code

greet.js

• This is our module
• It does not accidentally impact other code

//our first module

var greet = function(){
    console.log("Hello");
}


// notice you can call greet() here,
//but you can't call it in app.js due to security reason
// because a module does not ACCIDENTALLY impact other code
// *Module: A reusable block of code whose existence does not accidentally impact other code*

greet();


// allow you to make ariable a varibla or function
module.exports = greet;