AJAX - Client Side: JavaScript Overview
AJAX Client Side Step By Step Tutorial - part 2: JavaScript is heart of AJAX. If you still don't know anything (I know absolutely, it is not you!), we will talk a little JavaScript over here. We will talk completely about javascript at others tutorial series (next time).
JavaScript program designed to run in a browser has to be attached to a document. Most at HTML or XHTML document. But, future, we can attach at XML, SVG, etc.
To include JavaScript on an html page, we have to use <script> tag. Because script is not only JavaScript, tell to browser by adding a type attribut with a value of text/javascript.Look line 8-10 below:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<script type="text/javascript">
alert("It is me, JavaScript!");
</script>
</head>
<body>
</body>
</html>
Other choice, we can put JavaScript program to separate file. It is preferable because have several advantages:
- easier maintain
- reusable
Look example below:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>Untitled Document</title> <script type="text/javascript" src="example.js"> </script> </head> <body> </body> </html>
JavaScript file (named "example.js") will be downloaded by browser.
