Node module exports

Node module exports

Today our topic is node module exports. Could be a little tricky at the beginning but I prepared a simple example to sort things out a little bit. So without a further ado let code speak for itself:

file data.js

'use strict';

module.exports = {
  logHello: function() {
    console.log("hello");
  },
  logWorld: function() {
    console.log("world");
  },
  differentThing: function() {
    var thing = "something";
    console.log(thing);
  },
  otherThing: "other",
  ble: "blebleble"
};

Nothing to complicated just to show basic concept. We have wraped in ‘module.exports’ couple of functions and objects.

Now it is time to display it somehow, for that we will use separate file called display.js

'use strict';

var data = require('./data');

data.logHello();
data.logWorld();
data.differentThing();
console.log(data.thing);
console.log(data.otherThing);
console.log(data.ble);
console.log(typeof data.ble);

Here we are requiring our data.js file to have access to those exported functions and objects. And one by one we are calling them and therefore displaying them in the terminal.

Output of node display.js is as follows:

hello
world
something
undefined
other
blebleble
string

Pretty logical, but let’s go through one by one: First two lines are returning the output of functions logHello and logWorld We are calling them through data as it represents our exported content. With data.differentThing is the same story, but when we call data.thing we get undefined it’s because we want to call a variable which is defined inside a function. Scope in javascript won’t let us do it. When we call otherThing we are getting our content, because it is directly accessible (it is not inside a function). When checking what kind of object data.ble is we’re geting string which is exactly what it is.

At the begining it seems more complicated, then in for example Ruby but after couple of tries everyone should get the grasp of it. Hope it helped someone.

Cheers