Hello Script For JavaScript

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The next language to get the Hello Script treatment is JavaScript – my favorite language. Before we go any further, here is the definitions for Hello Script and JavaScript – just to make sure that we are on the same page…

Hello Script
‘Hello Script’ is a file that contains the most commonly used elements of a programming language so that it can be used as a cheat sheet when working with that language.
JavaScript
JavaScript is a client side scripting language that is used in browsers.

Code

Warning: Do not run this code – you will get a lot of alerts. If you have firebug extension, uncomment the first line – then you can run the code.


<html>
<head>
<title>Hello Script for JS</title>
<script type="text/javascript">
//alert=console.log;
alert("Hello World");

// Variables, concatination
var name = 'Binny';
var year = 2008;
alert("Hello, " + name + " - welcome to " + year );

//If,else conditions
if (year > 2008) {
	alert("Welcome to the future - yes, we have flying cars!");
}
else if(year < 2008) {
	alert("The past - please don't change anything. Don't step on any butterflies. And for the sake of all thats good and holy, stay away from your parents!");
}
else {
	alert("Anything wrong with your time machine? You have not gone anywhere, kiddo.");
}

// For loop
for(var i=0; i<3; i++) {
	alert(i + ") Hi there!");
}

//Numerical Array, While
var rules = [
	'Do no harm',
	'Obey',
	'Continue Living'
];
var i = 0;
while(i<rules.length) {
	alert("Rule " + (i+1) + " : " + rules[i]);
	i++;
}

// Associated array, foreach
var associated = {
	'hello'	:	'world',
	'foo'	:	'bar',
	'lorem'	:	'ipsum'
}
for(key in associated) {
	alert(key + " : " + associated[key]);
}

// Using Join and Split
csv_values = "hello,world,how,are,you".split(",");
alert(csv_values.join(":"));

// Function, argument, return, call
function hello(name) {
	return "Hello " + name;
}
hello_string = hello("Binny");
alert(hello_string);

// One for the OOP fanboys - Class, members, object and stuff.
function Movie(name) { //Constuctor
	this.name = name;
}
Movie.prototype.rateMovie = function() {
	this.rating = (this.name.length % 10) + 1; //IMDBs rating algorithm. True story!
}
	
Movie.prototype.printMovieDetails = function() {
	alert("Movie : " + this.name + "\nRating : " + this.rating);
}

//Create the object
ncfom = new Movie("New Country for Old Men"); //It's a sequel!
ncfom.printMovieDetails();

// Regular Expressions
string = "Hello World";
if(string.match(/^Hell/)) alert("Yup - its evil\n");
alert(string.replace(/l([^l])/g, "$1")); //Remove an 'l' from both words. Should alert('Helo Word'


/**
 * Specialized code
 */
window.onload = function() {
	var ele = document.getElementById("div-element");
	alert(ele);
	ele.innerHTML = "Hello World";
	ele.onclick = function() {
		alert("You Clicked?");
	}
	
	document.getElementById("text").value = "Goodbye World";
}
</script>
</head>
<body>

<div id="div-element"></div>

<input type="text" value="3" id="text" />

</body>
</html>

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