alexpilugin

Functional stateless (dumb) React component

function Hello(props) {
  return <div>Hello {props.name} </div>;
}

ES6+

const Hello = props => <div>Hello {props.name}</div>;

alexpilugin

1. $ mkdir app          /* create app folder */
2. $ cd app          /* move inside the app folder / /

• Before to install express.js you need to have minimum one of them:
• package.json or node_modules */

3. $ npm init          /* create package.json */
4. $ npm install express --save          /* install express.js locally */
5. $ npm install          /* install requested modules */
6. $ npm ls          /* [optinal] show a list of installed packages */

alexpilugin

var http = require('http');

http.createServer(function (req, res) {
    res.writeHead(200, { 'Content-Type': 'text/html' });
    res.end('<h1>Hello world!</h1>');
}).listen(3000);

console.log('Server started on localhost:3000; press Ctrl-C to terminate....');

alexpilugin

var http = require('http');

http.createServer(function (req, res) {
    // normalize url by removing querystring, optional
    // trailing slash, and making it lowercase
    var path = req.url.replace(/\/?(?:\?.*)?$/, '').toLowerCase();
    switch (path) {
        case '':
            res.writeHead(200, { 'Content-Type': 'text/html' });
            res.end('<h1>Homepage</h1>');

alexpilugin

function isEven(a) {
    if (a < 0) a = -a;
    if (a == 0) return true;
    if (a == 1) return false;
    return isEven(a - 2)
}

alexpilugin

var log = console.log;
var number = 8;
var line = " ";
var counter = 0, counter2 = 0;
while (counter < number-1) {
    counter++;
    line = counter % 2 ? " " : "#";
    counter2 = 0;
    while (counter2 < number-1) {
        var letter = (line[counter2] == " ") ? "#" : " ";

alexpilugin

function remove(array, index) {
    return array.slice(0, index).concat(array.slice(index + 1));
}

Array.prototype.remove = function (index) {
    return this.slice(0, index).concat(this.slice(index + 1));
}

//random 0 or 1:
Math.floor(Math.random()+0.5)

alexpilugin

var obj = {
	a: "a",
	b: "b",
	c: [0, 1, 2]
}

for (var key in obj) {
    if (obj.hasOwnProperty(key)) {
        console.log(key + ': ' + obj[key]);
    }

alexpilugin

var DATA = []; //or {}

//universal javascript module 
// This makes sure the data is exported in node.js
// `require('./{your_path}/data.js')` will get your data:

if (typeof module != "undefined" && module.exports) { 
    module.exports = DATA; 
}

alexpilugin

//returns array which includes all numbers from start to end (included)
function range(start, end, step) {
    if(step < 0) step = -step;
    if(!step) step = 1;
    
    if(end == undefined) { 
        end = start;
        start = 0;
    }
    var result = [];