nodejs

## Init package
    npm install -y
## Install live server
    npm install --save-dev nodemon
    or
    npm install -D nodemon
## Export a function
    const myFunc = (name) => console.log(`Welcome ${name}`);
    module.exports = myFunc;
    // saved in myFunc.js
## import/require a function
    const myFunc = require('./myFunc')
## Function Wrapper
Every file is wrapped in a function which allow us to access all its attributes

    //module wrapper function
    (function(exports, require, module, __filename, __dirname){
      
    })
## Path
    const path = require('path')
    // Base filename
    console.log(path.basename(__filename))
    > index.js
    
    // Directory name
    console.log(path.dirname(__filename)
    
    //File Extension
    console.log(path.extname(__filename)
    
    //Create path object
    console.log(path.parse(__filename)
    
    // Concatename paths
    console.log(path.join(__dirname, 'test','hello.html')
    
  
// Create directory

    fs.mkdir(path.join(__dirname, "test2"), {}, err => {
    	if (err) throw err;
    	console.log("Folder created...");
    });

// Create and write to file

    fs.writeFile(
	    path.join(__dirname, "test2", "hello.txt"),
	    "Hello World!",
	  err => {
		  if (err) throw err;
		  console.log("file created and text added...");
		  appFile();
	  }
    );

    const appFile = () => {
    	fs.appendFile(
    		path.join(__dirname, "test2", "hello.txt"),
    		"and I love node js!",
    		err => {
    			if (err) throw err;
    			console.log("text appended...");
    		}
    	);
    };    
    
    // Read data from a file
    
    fs.readFile(path.join(__dirname, '/test','hello.txt')