文档介绍：Introduction to JavaScript
Introduction
What is it?
How does it work?
What is Java?
Learning JavaScript
JavaScript Statements
JavaScript and HTML forms
What is JavaScript?
Browsers have limited functionality
Text, images, tables, frames
JavaScript allows for interactivity
Browser/page manipulation
Reacting to user actions
A type of programming language
Easy to learn
Developed scape
Now a standard exists – /publications/ standards/ECMA-
JavaScript Allows Interactivity
Improve appearance
Especially graphics
Visual feedback
Site navigation
Perform calculations
Validation of input
Other technologies
javascript.
How Does It Work?
Embedded within HTML page
View source
Executes on client
Fast, no connection needed once loaded
Simple programming bined with HTML tags
Interpreted (piled)
No special tools required
What is Java?
Totally different
A full programming language
Much harder!
piled language
Independent of the web
Sometimes used together
Learning JavaScript
Special syntax to learn
Learn the basics and then use other people's (lots of free sites)
Write it in a text editor, view results in browser
You need to revise your HTML
You need patience and good eyesight!
JavaScript Statements
<html>
<head><title>My Page</title></head>
<body>
<script language="JavaScript">
('This is my first
JavaScript Page');
</script>
</body>
</html>
Note the symbol for line continuation
JavaScript Statements
<html>
<head><title>My Page</title></head>
<body>
<script language=“JavaScript">
('<h1>This is my first
JavaScript Page</h1>');
</script>
</body>
</html>
HTML written
inside JavaScript
JavaScript Statements
<html>
<head><title>My Page</title></head>
<body>
<p>
<a href="">My Page</a>
<br />
<a href=""
onMouseover="('Hello');">
My Page</A>
</p>
</body>
</html>
JavaScript written
inside HTML
An Event