dineshdeveloper1/fs.js

## fs.js
//index.html
<body>
    <h1>Winter</h1>
    <p>I love the snow!</p>
</body>

//read file
var http = require('http');
var fs = require('fs');
http.createServer(function (req, res) {
  fs.readFile('index.html', function(err, data) {
    if (err) {
        res.writeHead(404, {'Content-Type': 'text/html'});
        return res.end("404 Not Found");
      }
      res.writeHead(200, {'Content-Type': 'text/html'});
      res.write(data);
      return res.end();
  });
}).listen(8080);

// create file --------------------------------
//appendFile
var fs = require('fs');
fs.appendFile('mynewfile1.txt', 'Hello content!', function (err) {
  if (err) throw err;
  console.log('Saved!');
});

//open file
var fs = require('fs');
fs.open('mynewfile2.txt', 'w', function (err, file) {
  if (err) throw err;
  console.log('Saved!');
});

//write file
var fs = require('fs');
fs.writeFile('mynewfile3.txt', 'Hello content!', function (err) {
  if (err) throw err;
  console.log('Saved!');
});

//update file -----------------------------------------------------
//append file
var fs = require('fs');
fs.appendFile('mynewfile1.txt', ' This is my text.', function (err) {
  if (err) throw err;
  console.log('Updated!');
});

//write file
var fs = require('fs');
fs.writeFile('mynewfile3.txt', 'This is my text', function (err) {
  if (err) throw err;
  console.log('Replaced!');
});

//delete file ------------------------------------------------------
var fs = require('fs');
fs.unlink('mynewfile2.txt', function (err) {
  if (err) throw err;
  console.log('File deleted!');
});

//rename file ----------------------------------------------------
var fs = require('fs');
fs.rename('mynewfile1.txt', 'myrenamedfile.txt', function (err) {
  if (err) throw err;
  console.log('File Renamed!');
});

## node-modules-type.js
// Core Modules ===================================================================================
const http = require('http');
http.createServer(function (req, res) {
    res.writeHead(200, { 'Content-Type': 'text/html' });
    res.write('Welcome to this page!');
    res.end();
}).listen(3000);

// local Modules ===================================================================================
// calc.js
exports.add = function (x, y) {
    return x + y;
};

exports.sub = function (x, y) {
    return x - y;
};

// index.js
const calculator = require('./calc');

let x = 50, y = 10;
console.log("Addition of 50 and 10 is " + calculator.add(x, y));

console.log("Subtraction of 50 and 10 is " + calculator.sub(x, y));

## node.js
//index.js
if(10 === '10' ){
    console.log('this is true')
}else {
    console.log('this is false')
}

// run the command
node index.js

//////////////////////////////////////////////////////////////////////
let arr = [2, 4, 98, 32, 8, 43]
console.log(arr[0])

/////////////////////////////////////////////////////////////////////
//app.js
module.export = {
    x: 10,
    y: 20,
    z: function{
        return 98;
    }
}

//index.js
const app = require('.app')
console.log(app.x)
console.log(app.a())

/////////////////////////////////////////////////////////////////////
//filter - find values in array
let arr = [2, 4, 98, 32, 8, 43]
arr.filter((item) => {
    console.log(item)
})

let result = arr.filter((item) => {
    return  item === 32
    //  return  item > 22
    //  return  item <= 32
})

console.log(result)


## url-module.js
var url = require('url');
var adr = 'http://localhost:8080/default.htm?year=2017&month=february';
var q = url.parse(adr, true);

console.log(q.host); //returns 'localhost:8080'
console.log(q.pathname); //returns '/default.htm'
console.log(q.search); //returns '?year=2017&month=february'

var qdata = q.query; //returns an object: { year: 2017, month: 'february' }
console.log(qdata.month); //returns 'february'
	//index.html
	<body>
	<h1>Winter</h1>
	<p>I love the snow!</p>
	</body>

	//read file
	var http = require('http');
	var fs = require('fs');
	http.createServer(function (req, res) {
	fs.readFile('index.html', function(err, data) {
	if (err) {
	res.writeHead(404, {'Content-Type': 'text/html'});
	return res.end("404 Not Found");
	}
	res.writeHead(200, {'Content-Type': 'text/html'});
	res.write(data);
	return res.end();
	});
	}).listen(8080);

	// create file --------------------------------
	//appendFile
	var fs = require('fs');
	fs.appendFile('mynewfile1.txt', 'Hello content!', function (err) {
	if (err) throw err;
	console.log('Saved!');
	});

	//open file
	var fs = require('fs');
	fs.open('mynewfile2.txt', 'w', function (err, file) {
	if (err) throw err;
	console.log('Saved!');
	});

	//write file
	var fs = require('fs');
	fs.writeFile('mynewfile3.txt', 'Hello content!', function (err) {
	if (err) throw err;
	console.log('Saved!');
	});

	//update file -----------------------------------------------------
	//append file
	var fs = require('fs');
	fs.appendFile('mynewfile1.txt', ' This is my text.', function (err) {
	if (err) throw err;
	console.log('Updated!');
	});

	//write file
	var fs = require('fs');
	fs.writeFile('mynewfile3.txt', 'This is my text', function (err) {
	if (err) throw err;
	console.log('Replaced!');
	});

	//delete file ------------------------------------------------------
	var fs = require('fs');
	fs.unlink('mynewfile2.txt', function (err) {
	if (err) throw err;
	console.log('File deleted!');
	});

	//rename file ----------------------------------------------------
	var fs = require('fs');
	fs.rename('mynewfile1.txt', 'myrenamedfile.txt', function (err) {
	if (err) throw err;
	console.log('File Renamed!');
	});
	// Core Modules ===================================================================================
	const http = require('http');
	http.createServer(function (req, res) {
	res.writeHead(200, { 'Content-Type': 'text/html' });
	res.write('Welcome to this page!');
	res.end();
	}).listen(3000);

	// local Modules ===================================================================================
	// calc.js
	exports.add = function (x, y) {
	return x + y;
	};

	exports.sub = function (x, y) {
	return x - y;
	};

	// index.js
	const calculator = require('./calc');

	let x = 50, y = 10;
	console.log("Addition of 50 and 10 is " + calculator.add(x, y));

	console.log("Subtraction of 50 and 10 is " + calculator.sub(x, y));
	//index.js
	if(10 === '10' ){
	console.log('this is true')
	}else {
	console.log('this is false')
	}

	// run the command
	node index.js

	//////////////////////////////////////////////////////////////////////
	let arr = [2, 4, 98, 32, 8, 43]
	console.log(arr[0])

	/////////////////////////////////////////////////////////////////////
	//app.js
	module.export = {
	x: 10,
	y: 20,
	z: function{
	return 98;
	}
	}

	//index.js
	const app = require('.app')
	console.log(app.x)
	console.log(app.a())

	/////////////////////////////////////////////////////////////////////
	//filter - find values in array
	let arr = [2, 4, 98, 32, 8, 43]
	arr.filter((item) => {
	console.log(item)
	})

	let result = arr.filter((item) => {
	return item === 32
	// return item > 22
	// return item <= 32
	})

	console.log(result)
	var url = require('url');
	var adr = 'http://localhost:8080/default.htm?year=2017&month=february';
	var q = url.parse(adr, true);

	console.log(q.host); //returns 'localhost:8080'
	console.log(q.pathname); //returns '/default.htm'
	console.log(q.search); //returns '?year=2017&month=february'

	var qdata = q.query; //returns an object: { year: 2017, month: 'february' }
	console.log(qdata.month); //returns 'february'