JavaScript 1 - Introduction

Created to “make web pages alive”
Functioning part of the webpage
Can write in HTML, executes automatically
Characteristics
- Full integration with HTML/CSS
- Supported by all major browsers, enabled by default
- Usually runs on client end
Properties
- Scripting Language
- Enables User Interactions
- Allows for dynamic updating of web content

Usage

Placed in
- <head>
- <body>
- external .js file
  - Seperating HTML and JS code will help manage the code base better
  - Designers can work along with coders parallel without code conflicts
  - Better readability of HTML and JS

<html lang=”en”>
	<head>
		<script type="text/javascript">
            alert("Welcome to my world!")
    </script>
	</head>
	<body>
		<!-- page content -->
	</body>
</html>

Basic JavaScript Syntax

Comments

//Single-line comment
/*multi-
line
comment.*/

Lines

document.write("Hello World");
//Lines end in ";"

Case Sensitivity

DOCUMENT.WRITE("Hello World"); //Does not work
document.write("Hello World"); //Works

Keywords

Some words are reserved, such as the ones below.