local module 3a export and log

1//// Writing Simple LOCAL Module 
2// Let's write simple logging module which logs the information, 
3// warning or error to the console.
4// In Node.js, module is placed in separate JavaScript file.
5// So, create a Log.js file and write the following code in it.
6// name of file Log.js Copy
7const log = {
8            info: function (info) { 
9                console.log('Info: ' + info);
10            },
11            warning:function (warning) { 
12                console.log('Warning: ' + warning);
13            },
14            error:function (error) { 
15                console.log('Error: ' + error);
16            }
17    };
18
19module.exports = log
20
21// In the above logging module we created an object with
22// three functions - info(), warning() and error(). 
23// Ending assigned object to module.exports. 
24// module.exports in above ex exposes log object as a module.
25
26// The module.exports is a special object which is included 
27// in every JS file in the Node.js application by default. 
28// Use module.exports or exports to expose a function, 
29// object or variable as a module in Node.js.
30
31// Now, let's see how to use the above logging module in our application.
32
33// Loading Local Module
34// To use local modules in your application, 
35// you need to load it using require() function 
36// in the same way as core module. 
37// However, you need to specify the path of JavaScript file of the module.
38
39
40const myLogModule = require('./Log.js');
41
42myLogModule.info('Node.js started');
43
44// In the above example, app.js is using log module. 
45// First loads logging module using require() function 
46// and specified path where logging module is stored. 
47// Logging module is contained in Log.js file in the root folder. 
48// So, we have specified the path './Log.js' in the require() function.
49// The '.' denotes a root folder.
50
51// The require() function returns a log object because logging 
52// module exposes an object in Log.js using module.exports.
53// So now you can use logging module as an object and call 
54// any of its functions using dot notation 
55// e.g myLogModule.info() or myLogModule.warning() or myLogModule.error()
56
57// Run the above example using command prompt (in Windows) as shown below.
58
59C:\> node app.js
60Info: Node.js started