JavaScript introduction
The script tag
The first thing you need to do is to add a script tag to the head of your document.
Direct JavaScript
You can enter JavaScript directly inline with your HTML using the script tag.
<head>
<script language="javascript" type="text/javascript">
<!--
-->
</script>
…Linking to a document
You can also write all your code into a separate document with the .js file type and link to it in your document.
<head>
<script type="text/javascript" src="mycode.js"></script>
…Declaring variables
To declare a variable in JavaScript prefix the name of the variable with the code var.
<script language="javascript" type="text/javascript">
<!--
var myVariable = 'string';
var myNumber = 0;
myNumber = myVariable;
-->
</script>The example above shows you how to declare a variable and also that you do not need to declare a type for your variable. A variable can change its type throughout the script.
Declaring arrays
To declaring an array use the following code.
var myArray = new Array();
myArray[0] = 0;
myArray[3] = 'string';This example shows you that arrays can contain different data types and do not need to have a size declared.
Writing functions
The example below shows you how to write a simple function.
function MyFunction(parameter1, parameter2)
{
return parameter1 + parameter2;
}